# More On ShortCuts In Multiplication

MORE ON SHORTCUTS IN MULTIPLICATION

Multiplying Two Numbers Whose Sum of Their Last Digits is 10 and Their Other Digits are the Same

Example One : 34 X 36

Solution by steps :

1) Multiply the first digit by one more than itself : 3 X 4 = 12

2) Multiply the last digits : 4 X 6 = 24

3) Combine the answer 1224

Short way : 3 X 4 = 12, 4 X 6 = 24 Answer: 34 X 36 = 1224

Multiplying Two 2-digit Numbers Whose Sum of Their First Digits is Ten and Their Last Digits are the Same

Example One : 64 X 44

Solution by steps :

1) Multiply the first digits and add a last digit: (6 X 4 ) = 24 + 4 = 28

2) Multiply the Last digits : 4 X 4 = 16

3) Combine : 2816

Short way : 6 X 4 + 4 = 24 + 4 = 28, 4 X 4 = 16

Answer : 64 X 44 = 2816

Try for yourself the following items using shortcut :

1) 35 X 75

2) 43 X 47

3) 86 X 26

4) 52 X 58

5) 39 X 79

Answers :

1) 2625 2) 2021 3) 2236 4) 3016 5) 3081

SOURCE :

21^{ST} CENTURY MATHEMATICS 6

## Comments

Wow, that's great! I've never come across those before and would love to find out why they work. Maybe if I have time I'll try to work it out! :o)

Thanks, the shortcuts may come in handy with any future maths teaching that I do.

44*12

Look at the left side of the equation and think 4 x 1 is 4.

Keep this number in your head.

Next add up the digit 1 and 2 and think, 3 x 4 is 12. Combine the numbers 4 with the 1 in 12. Think 52, this is the partial answer.

End with 4 x 2 is 8. Place the 8 at the end of 52, for the answer 528

With practice you will be able to do this in seconds.

Of course for multiplying by 12 you could always just write down the first digit. (4) Double the same digit and add the rightmost number. 8+4=12. Carry the one to the first number for 52, and double and place the last digit (8). 528.

Or, you could double the entire number (44) to 88. Carry the 8 to 44 for 52, and place the 8. 528.

I solved every problem, it works GREAT! thanks a lot for your work.

Its not working for some problems like

52*58, 62*72 , 63*53 and some other problems.

Please help me.

i knw left multiplication only thanks for rhs mul

thanks a lot

like it

i don't get how you got the answers at the bottom

super

niceeeee

it's a nice procedure...can u tell me short cut multiplication procedure of (3215*135)....please help me...

how to calculate 999*99*9 shortly......pls rply

it is super

how do we multiply this by shortcut way

9876*6742

salamats po//...

")))

16