Tuesday, January 19, 2010

NEAT MATH TRICK


Some people are such brainiacs.


The 11 Times Trick

We all know the trick when multiplying by ten – add 0 to the end of the number,

but did you know there is an equally easy trick for multiplying a two digit number

by 11? This is it:

Take the original number and imagine a space between the two digits (in this

example we will use 52:

5_2

Now add the two numbers together and put them in the middle:

5_(5+2)_2

That is it – you have the answer: 572.

If the numbers in the middle add up to a 2 digit number, just insert the

second number and add 1 to the first:

9_(9+9)_9

(9+1)_8_9

10_8_9

1089 – It works every time.


1 comment:

mary said...

Now that is a great trick! We are counting down the days until the wedding (64), and I wish you were closer so that we could plan a beautiful cake or two :)