Can you add these numbers in your head?

1. 80

   PlanksandNailsposted 11 years ago

   Can you add these numbers in your head?
   
   Take 1000 and add 40 to it. Now add another 1000 to it.
   Now add 30. And another 1000.
   Now add 20. Now add another 1000. Now add 10.
   
   What is the total?

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2. 80

   Neinahpetsposted 11 years ago

   Doing it in your head tricks you... eventually at the end you're saying 4900 in your head rather than 4090 because you're trying to remember, so you get 5000 in the head.... but that's 900 off.  It's 4100.
   
   Interesting brain teaser.

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3. 82

   peachpurpleposted 11 years ago

   Sorry, i am lousy at maths. I can't even add 25 and 7 properly. Usually uses my fingers to count them. ANyway, with the calculator, the answer is 4100. Definitely the best solution.

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4. 38

   wqaindiaposted 11 years ago

   I added another 1000 by mistake and it came out to be 5100.

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5. 57

   josephbarrettposted 11 years ago

   The total is 4100. It is a good question to get confuse anybody, at the 3rd 1000 i really got confuse but adding carefully, i got the right answer.

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6. 0

   JThomp42posted 11 years ago

   The total sum of these numbers would be 4100.

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7. 79

   joanwzposted 11 years ago

   The total is 4,100  easy, though I'm not normally a math person.

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8. 61

   cjpooja26posted 11 years ago

   Yes its a brain teaser and I counted 5000 but after adding 4 times 1000 and then adding the rest the I found the correct answer that is 4100

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9. 69

   pradiiphiraposted 11 years ago

   Its very simple.
   I solved in just ine try its 4100.
   Isn't it?

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10. 81

    blessedpposted 11 years ago

    I got 4100 after adding it twice.  In my first attempt I got 5100.

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11. 61

    duffsmomposted 11 years ago

    I usually do this kind of math in my head easily but I admit, I fell prey to the trick and my brain said 5000 at first.

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12. 59

    Little Grandmommyposted 11 years ago

    The answer is 4,100.  I love math.  It has always been one of my favorite things.  I love math problems and teasers too.

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13. 70

    kenyanXstianposted 11 years ago

    Its five K (5000) quite easy. Wait a minute,no that's 4100, there are only 1000 * 4 = 4000 + 100. That is tricky

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14. 61

    reddviewposted 11 years ago

    i like you PlanksandNails but this one had mischief written all over it...... so i chose 4100

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15. 74

    Caleb DRCposted 11 years ago

    OK Planks; I smell a trap. The commutative law of addition says the answer is 4,100, but there be a trap here. So I be taking another route. I think the first 1000 is a negative because you say take, like take away. The first and second 1000 cancel. We can add the 40 and 30, but you do not specifically say what to do with the 3rd 1000. I will assume add. Now we have 1070.  You do not say to add the other numbers to each other but I assume we can; therefore, we have 1070+1030=2,100. I doubt if I'm right here because I think it is deeper than this, but give others time to come up with the right answer. I'll be watching.

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    1. 80

       PlanksandNailsposted 11 years agoin reply to this

       You are the first to delve deeper, which means a clue. If you TAKE something and add to IT, what is ADDED becomes a part of IT.  Apart from IT, ADD. What is TAKEN and ADDED to IT, and what is ADDED, is the total.

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    2. 74

       Caleb DRCposted 11 years agoin reply to this

       --2,040 + 2060 = 20 ?

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