How to work out percentages
90
In order to find x percent of any number the general way of doing that is to multiply the number by the percentage. Since percentage means hundredths of any number, percentages are written with the decimal point moved two places toward the left-hand side. With whole numbers the decimal point does not show, and since moving the decimal point over one place would indicate tenths, examples of how percentages should be written before multiplying are: .05 (five percent) or .20 (20 percent). An example is find 40% of 80: Multiply 80 (since its a whole number you don't see the decimal point) by 0.40 (which is how percentages can be written, although the 0 before the decimal point isn't really necessary). The answer is 32.
Multiplying any number by any percentage (and remembering to include the decimal points in the answer) will give the percentage.
Quick tricks for finding percentages can be used. For example, if one wants to find 30% of a number s/he can start with the original number, mentally move the decimal point over one place (in order to find 10% really quickly) and then mulitply that 10% by 3 (because 10 x 3 =30). Any time the percentage involved is divisible by 10 this trick can be used.
Another quick trick for finding 5 percent is to move the decimal point over one place (again, to find 10 percent easily) and divide that result in half (because half of 10 is 5).
Finding percentages that are multiples of 5 (for example, 25) can be done in three steps: Move the decimal point over one place to get 10%, divide that figure in half to get 5%, and then mulitply that figure by 5 (because 5 x 5 = 25).
Also, knowing that 10% equals 1/10th of any number means that finding 10% can also be done by dividing by 10.
Most people are familiar with the fact that a quarter (25 cents) is 1/4th of 100 and that 50 cents is 1/2 of 100. Keeping those basics in mind, one can easy remember that finding 25% of any number means dividing it by 4 and that finding 50% of any number means dividing it by 2.
In the case of something like 75% figuring that out could be done either by using the above divisible-by-5 method or, if its easier, finding 25% and multiplying that by 3 (because 3 x 25 = 75).
A trick for finding 40% might be moving the decimal point over one to get 10% and either remembering that figure or writing it down. Then divide the number for which you're trying to find 40% of by 2. Once you have half of the number subtract that 10% you first figured out - and you've got your 40%.
The finding-10% trick/aid can also be turned into a finding=1% trick/aid. If you move the decimal point over two places you have found 1% of any number. You can easily multiply that 1% to get any other percentage simply by asking "how many 1's are in this percentage?". For example, to find 20 percent you can first find 1% and then multiply that 1% by the 20 (because there are 20 1's in 20). This will also let you find, for example, the 20%.
Finally, there is the issue of figuring out a tip in a restaurant. Again, the quick way (for 15%) is to move the decimal over one place to get the 10%, divide the 10% to figure out what 5% is, and then add together the 10% and 5%. A 20% tip is easier - just get the 10% and multiply it by 2.
Comments
I like your maths,
Thanks for very good lesson
Good tips, I always forget and have to call my husband...
i still dont get it
Oh noo..... don't tell me that. :) Let's see: One percent equals one one-hundredth of any whole. If you cut up a giant pie into one hundred pieces each of those pieces would equal one percent. Ten of those pieces would equal ten percent.
To find the percent of any number write a decimal point followed by the percent you want to find. For example, to write 40% as .40. What that means is 40 one-hundredths of the whole. To find something like 40% of any number multiply that number by the .40 (40% written in a way that lets you multiply). You'll get a number that shows that 40% of the whole is.
The trick for finding 40% quick is to remember that 40 is 4 times 10. Finding 10% is easy because to do that you just move the decimal point on place. (For example, 10% of 80 is 8. Finding 40% is just a matter of finding that 10% and multiply by 4 (because 4 x 10 equals 40).
So what is the percentage of 6% in 580 ?
Well, it is the 580 multiplied by .06 (the .06 represents 6 1/100ths). The answer is 34.80.
Another way to do it is to quickly realize that 10% of 580 can be found by moving the decimal point over one place, and getting 58.00. 1% of 580 can be found by moving the decimal point over yet one more place (5.80).
You can then find 6% by multiplying the 5.80 by 6 (because 6 equals 6 1's). Again, of course, you will get 34.80.
wow thank i got a A on my test
Excellent, 7th Grade Kid. :)
thank you your page realy help out a old timer like myself going back to school is a hard thing to do after you,v been out of it for so long.Thank again
thanks this helps i knew tis b4 but forgot it i havent used presentages in a while
Could you tell me how to work out what the % difference is between £16 & £17. Many Thanks
Great hub!!
Very detailed explanations..
There's this equation that says, 55% of 72 = ? But the thing is that I came up to the Ans: 95.4 and I'm confused because the answer is even larger than the real estate number set which is (72). Can someone PLEASE help we with this with sugar and ice-cream on top!!!??
Sincerely,
A 6th Grader :)
Lisa Hw your rea;ling smart at phsical and mental mathematics. If only you were here to help me with the thery But your not But reading all the Comments you posted can help me a little, WHY does mathematics have to be so HARD I'm only in grade 6 for crying out loud. Only 6 more years in school :(. Some one please help me!!!!!
Sincerely,
A confused 6th Grader That needs alot of help
Hope someone answers!!!
6th Grader: Sorry I took a while to see this, but here's my response:
55% of 72 is 39.6The regular way to find 55 percent of 72 would be to multiply the 72 by .55 (the decimal point shows 55/100ths, in other words, percent). If you had a dollar's worth of pennies, and separated out 55 of the 100 pennies you'd be looking at 55% of that dollar's worth of pennies.Another way to work it out would be:Look at easy tricks to figuring out .55%. Notice that you already know that there are 5 10's in 50.So decide to figure out 10% by moving the decimal over. Write that number down down.10% of 72 is 7.20.Now, though, you still need to figure out what the additional 5% is, but that's easy too:5 is half of 10, so 5% of 72 is 3.60 (because 10% is 7.20 you just divide it by two to find the 5%/half). Write down that 3.60 (the 5%).Since you've already figured out that 50% is half of 100% (of 72) you know that 50% equals 36.(You can either find that 50% by dividing the 72.00 by 2 or else multiply the 7.20 (10%) by 5 (because there are 5 10's in 50).You now that know have the 50% of 72. That is 36. You still have to add the 5% to it, though, because you're looking, of course, for 55% - not 50%.If you add that additional 5% (the 3.60 you wrote down before) to the 50%, you'll get the 39.60 (which is the 55% of 72.)You can check your answer by keeping in mind that 100 minus 55 equals 45. If you were to look for 45 of 72 you should come up with a number that, when added to your 39.60, should amount to 100% of 72. By multiplying 72 by .45 (percent - remember the decimal point) you'll get 32.40. If you add the 32.40 (the 45 percent) to the 39.60 (the 55 percent you got before), you'll find the two numbers add up to 72.00. That's because, again, 72 is 100% of 72 - and 45 and 55 add up to 100%.
Chikka, Math isn't always as hard as it can seem to be when you're in school. I'm not a math teacher, and math has never been my favorite subject (whatsoever); but when somehow all the things they try to teach in school just seem a lot easier once you get old enough to kind of see how easy things really are.
Something a lot of students don't realize is when they're "all nervous" and tense about homework or school subjects brain chemicals can actually change and make concentrating on what you're trying to learn more difficult.
What I recall about being around your age is not seeing math the way I eventually came to see it. As a student, I saw it as a bunch of unrelated things that were used to find numbers (or something like that). Once I got older I started to see that math is like a giant puzzles that makes one, big, picture (or whole) and that doing things like finding fractions and percents were really just different ways of seeing the pieces of that puzzle.
Another simple way to imagine math is to always kind of keep that picture of 100 pennies in your mind. You can imagine how you could multiply that dollar's worth of pennies by any number you want, or if there were a way to cut the pennies into tiny, equal, pieces, you'd be dealing with fractions (of 1). Math, though, is little more than ways of playing with those "pennies". Another way to see how math is nothing more than something that represents real stuff in the world might be to get something like a thousand Bingo chips or Poker chips; or else cut some paper into thousands of equal pieces and just play with it. Divide it into little groups of paper, add groups together, stack them up in equal stacks, and then make new stacks with different amounts of them.
I guess my point is that it's important not to think of numbers as "just numbers on paper" and math operations as "just isolated things you have to learn". While more advanced math can certainly seem a little trickier, in terms of drawing a connect connection to something like stacks of Poker chips or pennies, if you can get very comfortable seeing how 6th-grade math is pretty much a matter of that "whole" puzzle with all those different ways of altering the pieces of it; it may give you a sense of feeling more sure and ready to take on the more advanced math later.
I can give you some words to describe what I have on my desk right now, and you'll know that the words I type represent something very real and concrete. For example: cup of coffee, stapler, telephone. You have no problem knowing exactly what the words represent. Well, if I gave you a number that number would represent something every bit as concrete and real as the coffee cup, stapler, and phone are. If I tell you I have 4 books on my desk and tell you I'll take one away, you'll automatically imagine how I now have 3 books on my desk. The number of books I mentioned tells you nothing about what the books are, how big they are, or what color covers they have. Numbers represent, as you know, how many of anything there is, was, or will be. Numbers do a separate job than words do, but the thing with math is that it is about learning tricks for playing with numbers.
Maybe it would help if you could try to always imagine how every number in the world represents a poker chip or a part of poker chip.
Finally, something else that may possibly help you get a stronger feel for the way numbers fit together: Take a piece of paper, rule off ten or eleven vertical colums and, maybe, 20 horizontal rows. If you haven't already done this (or if it has been a while) start by making a multiplication chart with numbers 1 through 20 down the left-hand side, and numbers 1 through 10 or so across the top.
You'll find filling in the chart fairly easy, but as you fill it in notice there's a real "system going on" to the whole thing. Then try a different kind of multiplication chart. Try setting it up the say way but imagining, say, that you'll be paid 5.00 an hour for work. Down the side put something like "Week 1", Week 2", "Week 3" etc. and across the top head the columns with, say, 1 hour, 2 hours, 3 hours, etc.
Imagine how much you could make working different numbers of hours each week, and then once you have your whole chart done you could notice how you could do easily check on something like, "If I worked for 20 hours a week how much will I have at the end of Week 4?" "If I worked for 12 hours a week how much would I have by the end of Week 3?" It doesn't have to be hours worked. It could be number of DVD's you'll be collecting, number of music files, or anything. The point is if you make yourself some charts when you have a little fre e time you'll start to get a real feel for how math is that bunch of puzzles pieces that fit together.
Someone hasn't managed to help you feel sure of math. If you take a little time to make yourself some multiplication tables (strange as that may seem) you'll be using what you already know, as well as noticing a few things you may have missed along the way. You'll be the one in charge of setting up your own math problems and what you'll do with them. It's one of the best ways to get that proverbial "hands on" experience and knowledge.
I hope all these words haven't just been a giant bore to you (or anyone else), but when people can really see the relationship of numbers to real life things (even though sometimes though things are abstract) math can be pretty easy.
Not sure if this went through the stystem, but i just wanted to say that you should have a donation button on this page for all your hard-good work your doing!!
Good job;)
It did go through, but after I replied to your first post I thought of something I should have included:
Actually, yesterday I did run into a $700,000 house I wouldn't mind buying if I had the extra money. Do you think I could hire myself out as a "Sixth-grade, math-homework-doer" and earn enough to buy that 14-room house, which always looks so great at Christmas time? :)
In the interest of full disclosure, I was a kid who had no trouble learning math in elementary school, but when I got to seventh grade I was put in an "experimental modern math" class (which came to be the math that is now taught in schools). I did ok until my family moved, and because the new school didn't have the same math program the other school had, I was put in yet another and more advanced "modern math" class for a couple of years.
Maybe it was the sudden jump, or maybe it was the teacher, but from then on I never could see how that particular math "related to real life". I had my good grades in high school math under certain circumstances, but my inability to find high-school math "applicable to real life" (bizarre as that sounds to anyone who knows better, including my more mature and present self) made it close to impossible for me to "waste my free time" on math homework (!!!). So, whatever homework I did I did in English class (where the material came easily to me and didn't require paying attention).
As a kid, I blamed myself for not being able to make myself do what I truly wanted to do and knew I should be doing. I was about 40 years old when I finally figured out that I hadn't been lazy or careless. I had been without a teacher who knew enough to just point out how math applies to real life and gives us a new way to approach problem solving - even when the problem isn't a mathematical one.
Kindergarten and first-grade children are routinely shown the "apples and oranges" problems, but when kids get to sixth grade or so, and the math is no longer about simply adding and substracting, I think adults sometimes don't realize that some kids (maybe most) still need to see how something like Algebra is used in real-life problem-solving. Sometimes, too, maybe kids need to learn not just one way to find something like percentages, but a number of different little tricks that - when they see them - will help them see how it all fits together.
I grew up to be a person who is ok with math. In fact, I grew up to be a person who actually uses Algebra in my real-life problem-solving, even though I've chosen to work in areas that are more words- or people-focused. Still, I know the schools are full of kids who are - to one degree or another - like I was, with some having their grades only mildly affected but others having their academic journey more seriously harmed.
In a way I feel like a fraud, presuming to attempt to offer tricks on even something as elementary as percentages; but then again, there's a part of me that thinks there's a chance a "non-math" person may be able to explain things to another "non-math" person in a way the other person relates to more.
I don't over-estimate the degree to which my little percentages hub may be of any help to anyone; but if it turns out that it's of a little help to a few students who, for one reason or another, didn't quite catch on in class, then, to me, that makes the half hour or so I spent writing so much more well spent than it would have been on some other activities.
Again, thanks for your kind words. (I suppose, though, I'll have to wait on that 14-room house for now. Maybe if I'd had a better love of math when I was in sixth grade I would have become an architect or engineer, instead of dreaming of becoming an English teacher or social worker. :))
Thanks for all your help needed to look up on percentages for a test im taking and youve really helped :-)
We usually grab a calculator when we need some math. This info is so useful when there is no calculator at hand. Thanks
G'day Lisa
I finally do get it - you've put it so simply & I could use my calculator (at last!) to follow. You have a gift & it's so generous of you to share it with people.
My question is - Please can you tell me how do I get 2.4% of something - I thought about cheating and rounding it up to 3% to make it easier - but that doesn't improve my knowledge at all. I can understand when it's .25% or .75% but what about this sort of thing how do I calculate that?
Thank you so much for being you
Jen
Thanks for your nice words, Jen (but - believe me - it's no gift. It's more a matter of survival at the supermarket. :) )
Generally, I'd find 2.45% of any number by using the above "tricks" to find 24% of the number, and move the decimal point over one play to the left-hand side. For example, if you know that 24% of $100 is, of course, $24.00; then moving the decimal over one place to the left would give you $2.40 (which is the 2.4% of $100.00).
Another approach (that's easy but more complicated than the above quick approach) is:
Turn the 2.4% problem into two different problems: Since 2.4% is 2% plus 4 tenths of a percent, you could easily do it by first thinking of the number you're trying to find the percentage of, moving the decimal point over to get what 1% of that number is. Once you have the 1% you can then make the two different problems.
For example, if the problem is 2.4% of $100.00, you know immediately that 10% (or 1/10) of $100.00 is $10.00. That means that moving the decimal point over one place to the left will show you $1.00, which is, of course, 1% (1/100) of $100.00. (All the words I'm using to describe this initial process make it seems like a far bigger deal than really doing it is. )
Once you have your 1% keep that in mind (or write it down), because that's what will let you find your answers easily.
This is when you break the problem down into two very easy problems:
Since you want to find 2.4% you want to find 2% plus 4/10 of one percent.
The first thing is to find 2% by simply multiply the 1% by 2. In this simple case, since 1% is $1.00, mulitply that $1.00 by 2 is, of course, $2.00. You've got your 2% of $100.00. Keep that figure in mind, or write it down, until you do the second simple problem, which is:
Think about that 1% again ($1.00). Move the decimal point over one place to get get one-tenth of a percent (because now you're working with the numbers on the right-hand side of the decimal point 2.4%). Moving the decimal point will turn the $1.00 into .10 (ten cents). Since you now know that .10 is one-tenth of one percent, all you have to do is multiply it by the 4, and you'll get the .40 cents, which is 4/10 of a percent of $100.00. (Again, all the words make the problem look like a far bigger deal than it really is.)
Now that you know that 2% of your $100.00 is $2.00; and that .4% of $100.00 is .40 cents, all you have to do is add them together. You get $2.40 (which is, of course, the $2.40 you would get by figuring out 24% and moving the decimal place over one place).
In other words turn the problem into two little problems, dealing separately with the numbers on each side of the decimal point . Then add them together.
Thanks again, for your kind words. :)
Hi Lisa, i wanted to work out the difference in percentage between two figures. How would I work out the difference (in percentage) between 29,000 and 3,500. Basically both those figures are average attendances for football matches between 2006 and 2007, i wanted to find out how much in a percentage the attendence has dropped in the year. Thanks for your help :)
Hi Lisa, i wanted to work out the difference in percentage between two figures. How would I work out the difference (in percentage) between 29,000 and 3,500. Basically both those figures are average attendances for football matches between 2006 and 2007, i wanted to find out how much in a percentage the attendence has dropped in the year. Thanks for your help :)
Hi, James. This particular type of calculation goes a little past the kind of "quickie mental tricks" I have for percentages that apply to grocery shopping, tips, and sales taxes. Most people would prefer to use a calculator for this type of calculation.
What you would need to do is figure out the difference between 29000 and 3500 (which is 25500). Because you're interested in what percentage 25500 is of 29000, you would divide the 25500 (the difference) by 29000. After calculating that, you would multiply the answer by 100. Depending on what you're doing you may choose to round, but if you do there will always be a slight discrepancy if you try to "back check" your figures.
(In other words, it used to be 29000 but went down by 25500, so what you need to know is what percentage of that original number (29000) is that 25500. )
You can check your calculations by figuring out what percentage of 29000 the 3500 is (divide 3500 by 29000 and multiply the answer by 100). Once you have what percent (parts of 100%) 3500 is, you can substract that percent from 100 - and you should get an answer that shows what percent of 29000 the 25500 is. (The 3500 is x percent of the original 29000, and the 25500 difference is x percent of the original 29000, and those percentages should add up to 100% of the 29000).
I got 87.9 for 25500; and 12.1 for the 3500. The 87.9 and 12.1 add up to 100%.
I'm including here links to a few sites that do a more "professional" job of explaining how to do this type of calculation (in order of helpfulness, in my opinion). I'm also including a "non-professional" link that adds a simple remark that may be worth including.
This is an excellent one (scroll down to where this type of calculation is done):
http://www.copydesk.org/words/math.htm
Here is one that shows it in a different way:
http://mathcentral.uregina.ca/QQ/database/QQ.09.06
These three links are also good:
http://www.helpingwithmath.com/by_subject/percenta
http://download.oracle.com/docs/html/B13915_04/per there's someone's simple remark on a non-math site:
http://answers.yahoo.com/question/index?qid=200708
I just dont get it! I must be the dumbest man on the planet! (with poor spelling to!) Im trying to work it out by hand and its just not coming to me what shall i do?
I was trying get to girips with 30% of 72 by hand, i have an exam in london and they, for some reason feel the need to ban calculators!
Tes, I'm guessing you have too much on your mind. That's probably the biggest reason people have trouble getting math steps. For 30% of 72:
You could first find 300% (which is 3 times 100%) and then move the decimal.
Here's a typical example of a trick to do in your head:
You know that 3 times 7 is 21, so 3 times 70 is 210 (the decimal point moved over one place). You know that 3 times 2 is 6. If you add that 6 to the 210 you got when you multiplied 70 by 3; you'll have 216.
216 is 300% of 72, but you don't want 300%. You want 30%. To find that just move the decimal point over one place toward your left. 216 divided by 10 is 21.60 (don't forget you have to add that zero as a place holder when there is only one digit after the decimal point).
A different approach would be to find 10% of 72 and multiply that by 3 (because 30 is 3 times 10):
To find 10%, just move the decimal point over one place toward your left (in other words divide 72 by 10): Moving the decimal point to show 1/10 (which is 10%) in 72 would result in getting 7.20.
Once you get that 7.20 (which is only 10% of 72) you would want to multiply it by 3 (because, again, 30% is three times 10%). Multiplying that 7.20 (you got when you moved the decimal point over) by 3 (because you need 30% instead of the 10% you now have) will get you 21.60.
Yet another different trick finding 300% and dividing by 10:
Think of the 70 as one thing. Think of the 2 as another thing.
Think of 3 times 70, and you get 210. Think of 3 times 2 and you have 6.
Add the 210 and the 6 - and you have that 216. That's 300% of 72. Now just think of what one-tenth of that would be, and that, of course, would be the 21.60 (because you moved the decimal point over, which is what you do any time you want to find one-tenth of anything).
here is one i have a litre of in which fifty percent is alcohol now how much water do i put in to make it 35 percent and or how would i calculate that
I'm going to use a half gallon (64 ounces) as an example of how to work it out (and assume no evaporation is going to be allowed to happen).
You know that right now you have 32 ounces of alcohol. You need to figure out how much 32 ounces is 35% of. First, you write the 35% as .35.
You know that 32 amounts to .35 of something (call it "x").
A different way to say it is: 35 x (think of it as "35 somethings") = 32.
How do you figure out how what x is? How many "somethings" go into 32 35 times? You would divide 32 ty 35, BUT because you're dealing in a percent you actually divide the 32 by .35 (the way you wrote that 35% above).
By dividing 32 by .35 you would get: 91.42857
You can check that answer by multiplying the 91.42857 by .35 (35 percent), and you'll get 32.
If you round off the answer you'll get 91.43 or 91.4, depending how much you want to round. You could also round to the 91 (because 43 is less than 50).
You're not done yet, though:
Now you need to subtract 64.00 from 91.43 to see how much water to add. 91.43 minus 64.00 = 27.43 ounces. If you didn't round you'd get 27.42857 ounces.
Again, you could double-check by calculating 35 percent of 91.42857. If you multiply that 91.42857 by .35 you will get 32.
Note: It's before 6:00 a.m. on a Monday morning. I'm pretty sure all this works out; and I hope I helped make things clearer; but if anyone notices some error in my wording - I'm not responsible!
Thanks Lisa!!!! You helped me out a great deal with your wonderful explanations, thanks again!
What is the 7.65% Social Security/Medicare tax on a paycheck of $430?
Thanks Lisa for the refresher and tips
you need to be a teach, you dont even need a calculator for this...
I'm going to have to come back and read this one very s-l-o-w-l-y. But it's looks better than any math book I've seen!!
Wonder what your IQ is?!? :-))))
Thanks, Proud Mom. With what I know you've had going on with your child recently, I can imagine how you may not have much interest in thinking about math right now.
I don't really know what I have for an IQ, but I don't think my fair understanding of junior high math is particularly an indication of much of anything. :) After the day I've had today, I think my IQ is about 45 right now. :)
Thanks, Proud Mom. With what I know you've had going on with your child recently, I can imagine how you may not have much interest in thinking about math right now.
I don't really know what I have for an IQ, but I don't think my fair understanding of junior high math is particularly an indication of much of anything. :) After the day I've had today, I think my IQ is about 45 right now. :)
To Sandy, who sent me the e.mail, "How do I figure a percentage of 77 out of 300? What would be the percentage?"
The calculator way is to multiply 300 by .77
An easy, in-your-head, way may be to first find 1% and 10% and work from there.
Since you know that 10% (one-tenth) of 300 is 30, you can just move the decimal to see that 1% of 300 is 3 (or you could have just divided the 300 by 100 to get the 3, but sometimes the first way I mentioned can seem clearer to some people).
Since you know that 30 is 10% of 300, all you have to do is multiply 7 times 30 to get 210 (which will you show you what "70 of that 77 percent") is.
Since you don't just want to know what 70% is, and need to know what "that additional 7% is), multiply that "additional 7" by the 3 (because the 3 is 1% of 300; so you're seeing percentages in "single units" for that additional 7).
Anyway, 7 x 3 is 21. So now you would know that the 70 part of that 77% is 210; and you would know that the 7 part of that 77% is 21.
If you add the 210 (70%) to the 21 (7%) you will get the whole 77% of 300.
Wow great site and exellent tips thanks...
steve, thanks (apparently, ibro, a couple of comments up, doesn't think so :) )
rachael, I don't know if you'll see this note, but I'm posting it anyway. I'm sorry I didn't see your e.mail until long past when my answer would have been helpful to you. Apologies.
Read this post right before I posted my version of dealing with percentages. I wanted to make sure i wasn't stepping on toes. Good stuff.
I love math tips! Thanks.
i dont get it
6.25% or 300 is 18.75 not 18.25
says, thanks. Someone else pointed that out. It started with a typo ages ago. I thought I had fixed it. I've removed the errors for now until I go back over it, see what typos was fixed or not fixed, and make whatever corrections have to be made as a result of it.
you are wonderful!! i really enjoyed reading all of your responces :) You would make a fabulous teacher!!
Could you try and explain this one that came home as my 10 year old daughters homework.
Mr Baker buys some perfume for 12 dollars and a book for 5 dollars,
He calculates that the perfume cost £4.80 and the book cost £2.00
How much would a 7 dollar t-shirt cost in pounds?
Thanks
tearing my hairout, sorry I haven't seen your comment until just now (six hours after you posted it). From what you have here, there isn't particularly a percentage problem, as it is a currency conversion one. You can find online currency converters that will convert pounds to dollars and or dollars to lbs. Here's one (but don't go to it until you read the last half of this response to your question, because I don't think the problem is really about the current conversion rate):
http://www.dollars2pounds.com/
I'm not sure what work your daughter's teacher wants her to show, if any, beyond converting the 7 dollar shirt into pounds. The converter above shows that the shirt would 4.28 pounds.
Based on the converter I used just now, the 5 dollar book would be 3.06 pounds. The conversion rate changes. The converter I used shows that the 12 dollar perfume would be 7.34 pounds. The total for the book and perfume are 10.40 pounds. I'm guessing the problem, though, is based on whatever conversion rate is presented - not the current one.
Current conversion rate aside, if you divide the 12 by 4.80; and if you divide 5 by 2.00, you'll see that the teacher's conversion rate is 2.5. Based on that, there would be 2.5 dollars for 1 pound. If you divide the 7.00 by 2.5 you get 2.80 (pounds). The total Baker spent in pounds is 9.60 pounds.
You can double check that by adding up in dollars what he spent (12, 5, and 7), which comes to 24 dollars. If you divide the 24.00 by 2.5 you will get 9.60 pounds.
I'm guessing what the teacher wanted students to know is to first find the conversion rate by dividing dollars by pounds; and then use that to figure out the rest of the problem.
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Comments
I think you should have a Donation button on this page for all your good-hard work your doing!! really!!
Good job:)
Thank you. A donation button sounds good to me, but I don't think HubPages would approve. :)
Timely topic, thanks! WHo can't use this?!
Is this a Junior High Math Study Board?
It's not, but if whatever is already here is of use to any junior high people, all the better.
I get it...tnx!
Thank you so much I finally got it!!!!
QUESTION? 6 MISSED PICKUPS IS WHAT OUT OF 100%.
6 is 6% of 100. 94 made pick-ups would be 94%.
how would you find the ordinary price of an item if the item is $463 because it was 35% off. how would u find the original price of it..
Lee, for a problem like finding out "what $463 is 35% of":
There is a response to "James'" comment above that tells how to get the answer to such a problem; but there are also links (show in the response to James) that may be explain that kind of calculation better. :)
ummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
so how wou;d you find 78% of 90
The "usual" way would be to simply multiply 90 by .78.
You need to figure out 70% and 8% and add them together to get 78%. Figure out 70% by knowing that 10% of 90 is 9. Multiply the 9 that 9 by 7 (get 63). Then know that since 9 is 10% of 90, .9 is 1% of 90. Multiply 9 x 8 (get 72), but because 9 is 10% (not 1%) you need to add the decimal that will divide the 72 by 10. (7.2). In other words, when thought of that 10% of 90 (9) that would get you the 70% because 70 is a two-digit number and ends with 0.
Because the 8 is in the "ones column" (as compared to the 7 in 70 that's in the "tens column") you have to add that decimal that will turn the 72 you get when you multiply 9 x 8 and make it one-tenth of 72, which is 7.2.) 63 (which is 70%) and 7.2 (which is 8 percent) equal 70.2 when added together.
From a slightly different approach:
Another mental trick may be to think of what 1% of 90 is (.9 because you've moved the decimal point over two places). From there, temporarily forget about the decimal point.
Break down the 78 into 70 and 8.
Think of how 7 x 9 = 63 Because you want to five 70% (not 7%) percent, though, and because there is that 0 after the 7 in 70, by not returning that decimal point "mentally removed" you are allowing for the fact that 70 is ten times 7. In other words, don't return the decimal point you took out if you're looking for a "two-digit percent" like 70.
Next, multiply 8 x .9. This time, though, return that decimal you mentally removed because 8 x 9 will get you 72 but because you really should have been multiply .9 (which is 1% of 90) by 8, you have to return that decimal point.
All these words make it all seem complicated; but the mental actions involved go really quickly.
So, what you end up with is that you have come up with 70% of 90 (63) and 8% percent of 90 (7.20). Then just add the 63 and the 7.2 (because you're adding 70% plus 8%) - and you'll get the 70.2 (which is 78% of 90).
A quicker trick may be to instead figure out the easier 22% of 90 and then substract that from 90 to get the 78%. The reason this may be easier is because all you have to do is find the 1% and double it.
If you figure out the 20% by thinking of how 1% of 90 is .9 (so remove the decimal point before figuring out 20%), you'll end up with 18.
If you then divide that by 10 (because 2% is one-tenth of 20%), you'll end up with 1.8.
Since 18 plus 1.80 = 19.8 - that's what 22% of 90 is.
Then substract the 19.8 from the 90 - and you end up with 78% of 90.
The only reason I suggest the "22% approach" in this case is that 22 has the same number (2) to deal with. It can make things that much simpler when figuring out things mentally. Also, because 2 is so close to 1, it makes things that much easier again.
Sometimes how to mentally figure out a percentage can best be approached by first asking what would be the simplest and most "mental-friendly" approach.
Yet one other approach (maybe the quickest):
Aim to figure out the 22% (because it's the smaller and easier number) and later subtract that from the 90.
You know that 10% of 90 is 9, so 20% of 90 will be 18.
Now figure out 2% (because you need to figure out 20% and also 2% to get 22%) by knowing that that 2% is one-tenth of 20%. Once you know that 20% is 18 you can easily realize that 2% is 1.8 (the decimal point made the difference).
From there, simply add the 18 to the 1.8, and you'll get the 19.8. You will have the 22% of 90, so all you have to do is substract that 19.8 from 90 to get 78%
A quick mental trick to substract something like 19.8 from 90 is to think of the "nearest easy number" (in this case, 20) and substract that from 90. (90 minus 20 is 70). Because you know that substracting 20 from 90 is subtracting a little more than the 19.8 you have to think of the difference between 20 and 19.8 to know how much you need to substract from the answer you got (because you substracted slightly more than than the 19.8). In this case, the difference between 19.8 and the 20 you used for convenience is .2. So add the .2 to the 70 you got when substracted 20 from 90.
I love maths/calculations and have always been good at it. These simple yet very essential tips really help to save time specially during apptitute tests ;)
Thanks, kashifmahmood. They come in handy during grocery shopping too. :)
I need to know how to change the decimal place that appears on your answer. it comes out with tenths, I need it to be with the hundreths. Instead of 6.5, I need 6.54. Can anyone help?
Laura, I'm not quite sure exactly how to interpret your question. (Maybe it's me, and it's late - but I'm assuming you want an answer quickly.)
Moving the decimal point over 1 place (toward your left) will divide a number by tenths. With an example like 600 (you shouldn't see the decimal point, but I'll add where it's "implied") would be 600. If you move it once toward your left you'll essentially divide 600 by 10 (60.) Move it once more to your left, and you divide it by 10 again and get 6. (Again, the decimal points shouldn't be there, or else they should have a zero after them.)
To further divide the above example by ten, you would move the decimal point in 6 (or 6.0 once toward your left and get .6 (6 tenths). Move it again once, and you have .06 (there zero makes a "spacer" in this case).
With 6.5 you're dealing with one whole number (the 6) and the .5 (5 tenths because it is one place after the decimal point).
Assuming you need to move the decimal point at all (there is such a thing as 6.5%, but I'm assuming that isn't the case here), you would move the decimal point in 6.5 over once toward your left and get .654 to reflect a percentage (hundredths and a little more than you may want/need). Depending on how accurate you want to be, you could leave .654 or else round the 4 (and because 4 is less than 5 you would drop it off to round things off).
If you were to try to check your math "backward" by using the .65 you would find it just slightly off; but if you checked it by using the .654 you would come up with an accurate figure that proved your math was correct.
Help! I'm a 6th grade student trying to find out how what percent of increase is it when you start at 57,500 and increase it to 62,250?
Linda, first you have to figure out the difference between the original 57,500 and the new 62,250. You probably already know that you just just substract the 57,500 from the 62,250 - and get 4,750.
The way to figure out what percent of 57,500 the 4,750 is would be:
Divide the 4,750 by 57,500 (on a calculator is always easiest), get the answer, and the multiply that answer by 100. In this case you need to round, because there's a string of numbers beyond the "hundredths" space in the answer.
If you divide 4,750 by 57,500 you get 0.082609. You then can round it off.
A kind of backwards way to find the same thing (just so you can maybe see what's going on with this type of problem) is this:
You can figure out how many "4,750's" go into 57,500. Since it cannot be evenly divided, you'll come up with a figure that represents a fraction of the 57,500.
If you divide 57,500 by 4,750 you get 12.10526. That tells you what part/fraction of 57,500 the 4,750 is.
Since you need to know what percentage of the whole 57,500 it is (and since 57,500 is 100%, or ALL, of itself); you can divide 100 by that 12.10526 to come up with a percentage too. Again, you need to round.
(I hope I wasn't too late responding here, and I hope I didn't make any stupid errors - kind of bleary eyed at this time of night, but I didn't know if anyone else would see your comment and respond.) (Actually, I did make a stupid error but caught at least that one. )
what is 1%
Not sure I understand if the question is related to an above comment, or just a question about 1% on its own; but I'm assuming a general question:
If you have "all of" something (any number) it is like having 100 equal little pieces of it. Those "equal little pieces of it" are 100 little "pieces" in the form of a single percent each (1%).
Showing 1% of any number is done by moving the decimal point over two places in the direction of your left hand. After you move the decimal point, if there are a string of number after it you either round them up/down (in a situation like when you're figuring out sales tax); or you could leave them until all the "figuring out" has been done before rounding (or choosing not to).
You can think of it as if any number is something like a cake. A small number is a small cake, and the the bigger the number the bigger the cake; still, what 1% is this: If you cut any "cake" (number) into 100 little pieces, each will represent 1%.
50 pieces of that "cake" means 50 little pieces that are each made up of 1%. (50%) 25 pieces of "cake" means, of course, 25%.
This will surely increase your ranking.... Very detailed explanation.
JPSO138, this hub has surprised me. It was a request I saw ages ago, and I thought, "I can answer that easily enough - think I'll answer the request." It has surprised me that anyone other than the person who made the request has even looked it. Based on the surprising number of e.mails I've gotten from this hub, I guess a lot of junior-high aged students seem to have liked it. It's not my best piece of writing, by any means, but I kind of like that it has apparently been useful to some students.
i hate it does not helr
you really help me thank you
wonderful, sorry if it didn't help. If you have the time, and want to ask a specific question, I'd be happy to try to be help.
jada, thanks. Glad it helped someone. :)
That is excellent. I liked it Lisa. As I am looking forward to the Management aptitude exam , this tutorial would be the boon for me.
Thanks for your efforts.
Please do write some other articles on various other tricks.
I appreciate your dedication.
i think this site help me a lot but the site was BULLSHIT
Ibro, this site was prepared in answer to someone's request about how to find percentages. It was the aim to show some quick tricks to help people figure it percentages easily (maybe at the supermarket or when figuring out a restaurant tip, etc.)
I used a casual, "non-math", style of wording because I figured if someone has trouble with figuring percentages they are either very young or else people who benefit more from "non-math"/more casual explanations.
I have no doubt that this page is not what a lot of people, looking for math information, will be looking for. Based on feedback/traffic it gets, however, it is apparently what has answered some people's question about how to figure percentages easily. Based on several nice e.mails I've gotten from junior-high age students, they are generally the "audience" for this site; but based on those e.mails, I have to say that I don't call it "BS" if a page has helped even a few kids learn their math. My thinking has been that the world is full of more "formal" or "advanced" sites/books and even people who teach math, and none of it apparently got through to some of those kids who e.mailed me (at least when it came to figuring out percentages).
So, this page is an "unfancy"/"folksy" attempt to share some quick percentages tricks with anyone who has/had trouble with doing that. Nobody is pretending it's anything more important or useful than that. I have no doubt many people will find it is "BS" (that's ok), and I do think it's unfortunate if it hasn't been helpful to you, as you had thought. I hope you found the kind of helpful information you were looking for, and remind you that search engines don't always "know" exactly what you're looking for, and send you a bunch of different sites in search results.
How do I determine the percent of each person's percentage of the vote. For example, if a person got 161 votes, how do I get the percentage of that number of votes. It might read 161 or "percentage. What are the steps?
I know how to get percentage of a product discount and so on, no problem.
thanks
Tiffany, you'd need to know the total number of votes in addition to how many votes someone got. From there you would use the same approach you use to find out what percent of one number another number is. In other words, if there were a total of, say, 500 votes you'd need to figure, "161 is what percent of 500". If I understand the type of "product discount" percentage problem you mentioned correctly, this would be an example of that:
Product used to sell for $100. Today it's on sale for $80. To find out the percentage of the "discount" you'd first consider the $20 difference; and then ask "what percent of $100 is $20". That step, there, is the same as you'd use for the voting question (minus the dollar/cents factor).
i still dont get it (:sos:)
all sounds like archish to me (language bezzies made up don't get it) thanx though
How would you work out 22% of 25%???
Serina, first you'd figure out how much 25% is. A quick way is to divide the number you're dealing with by 4.
Another way is to figure in your head: What is 10% of the number in question. Then think of half of that 10%. (which will tell you what 5% is). Multiply whatever number is 10% by 2 (because you want 20%) and then add the number you got for 5%.
Now that you have whatever 25% is, you want to find 22%. The easiest way is to think of what 10% is by moving the decimal point over one place. Multiply the number you got (for 10%) by 2 (because 20 is two times as much as 20).
Now think of what 1% is by moving the decimal point over one more place (from where it was after you got the 10%). Again, multiply the number you get (for 1%) by 2 (to account for that extra 2 over the 20%).
Add the number you got as 20% to the number you got as 2%, and that's 22%.
Ok, how do I find out what the percentage is of something? If I am making something and I add 3.5 oz. base ingredients and add.5 oz. of another ingredient, what is the percentage of the .5 oz to the whole thing?
Kristi, I don't have any quickie mental tricks for that (and actually, I've been sick for a couple of weeks and can't really concentrate to write). So, I'm including this link, which shows the conventional way to figure out that type of problem:
http://www.ehow.com/how_2364017_percentage-numbers
http://answers.yahoo.com/question/index?qid=200901
Actually, here's a site that will do the calculation for you:
http://lachie.net/maths/percent.html
I may think of a mental trick for that in the near future. Sorry not to be of more help.
im really struggling the best way to work out this problem please, please help out of 800 shoppers 300 shop more than three times a week. What percentage of the shoppers shop more than three times a week? i know theres got to be an easy way
Chris, you need to figure out what percent of 800 300 is. The way to do that is to divide 300 by 800, and then multiply that by 100. What you're essentially doing is figuring out how "800 units" can be equally divvied up among 300 "units". Then, because percent is hundredths, that's why you multiply by 100.
In this case, you'll find that 300 is 37.5 percent of 800, so that's your answer.
A different way to do it is to realize that 8 is 1% of 800 (percent is hundredths, and you get that by moving the decimal over two places; so you can do it in your head). Once you know what 1% is you ask, "How many 1%'s go into 300?" If you divide 300 by 8 you'll see that you get the 37.5 as well.
Just as a tip for getting a rough idea of how big a number you're looking for: You know that half (50%) of 800 is 400, so you'd know ahead of time that because 300 is less than 400 you'll be looking for a percentage under 50%.
Another "grounding" tip: You know that 10% of 800 is 80, so it's easy to know that 20% would be twice that (160). 30% would be three times 80 (240). At this point you may see that the 240 is getting kind of close to the 300; and, again, you know that 50% is 400. Again, this kind of thing can give you some "grounding" about the ballpark you're looking for.
Chris, just another overlooked "grounding" tip: Since you know that 4 x 80 is 320 (because you know that 4 x 8 is 32, and you're just dealing with the extra zero/tens), you'd also know that 320 is higher than 300. That means you can know that the answer to "what percent of 800 is 300" is going to be between the 30 and 40 (%) - in other words, in the 30's.
Very well written hub .....
very much informative ......
Thank you very much for your great hub, for good advice, good wishes and support. Thanks for sharing your experience with all of us.
Sexy jonty, thank you for the kind words. :)
Excellent hub topic.I think your tips gonna help me to figure out restaurant tip in a few seconds.
andromida, thanks. :)
In the words of R. Kelly, "Everybody feelin freakyyyyy!!!!!"
William, I'm not sure how your comment relates to the subject; but I have to admit it adds a little "lightness" to an otherwise boring topic. :)
Author's Note: Somewhere in my account I ran into a comment that pointed out an error. That comment isn't showing up here, even though I approved it; so I don't quite know what's going on there.
In any case, I will return later to look for both the comment and the error pointed out by it. There's been a lot of a quick typing and "math gymastics" going on when I've tried to do things quickly here - so, again, I'll be back to correct the error and see whatever happened to that comment.
Good article on working out percentages thanks, maryladd
very nice article.....
keep up the good work ....
thanks ....
Just what I was looking for thanks a lot:)
Del, great. :) Thank you.
you keep mentioning move the decimal point over one....LEFT OR RIGHT ? Just to make it perfectly clear.......Ü
dogboy, to find something like 10% of, say, 50 you'd imagine that with the 50 the decimal point (which isn't ever written for whole numbers) would be after the zero (like 50. ). If you were dealing with 50 dollars it would, of course, be written out 50.00. So, keeping in mind where the decimal point (written or not written) is with any number...
To find something like 10% you would move the decimal point over once toward your left. With the 50. you'd move it from being after the zero to being after the 5, which would give you the 5 as 10% (1/10th) of 50.
Albert says:
2 years ago
wow thanks alot u helped greatly. i owe u.