Wednesday, February 20, 2013

One cool math trick

An easy way to multiply by 11

11 X 42 = 462
This is obtained by
First digit of the number : 4
Adding the two digits: 4+2 :6
Last digit of the number: 2
So, the answer is 462 !!

Let's try another one.
11X48

Here, 4+8 = 12, its greater than 9, so add a carry to the first number

First Digit: 4
Last Digit of Adding the digits 8+4: 2 (carry 1)
Last digit: 8

So the answer(don't forget the carry)
528!

Try some at home with your school aged child over dinner today :)

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