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SHORT TRICK TO MULTIPLY ANY TWO DIGIT NUMBER BY 11.

 

SHORT TRICK TO MULTIPLY ANY TWO DIGIT NUMBER BY 11.

This post is made to learn “How to multiply, in your head, any two-digit number by eleven?” It’s very easy once you know the secret.

Consider the problem:

32 x 11

To solve this problem, simply add the digits, 3 + 2 = 5, put the 5 between the 3 and the 2, and there is your answer:

352

Now you try:

53 x 11

Since 5 + 3 = 8, your answer is simply

583

One more. Without looking at the answer or writing anything down, what is

81 x 11?

Did you get 891? Congratulations!

 Now before you get too excited, I have shown you only half of what you need to know. Suppose the problem is

85 x 11

Although 8 + 5 = 13, the answer is NOT 8135!

As before, the 3 goes in between the numbers, but the 1 needs to be added to the 8 to get the correct answer:

935

Think of the problem this way:

1

835

935

 Here is another example. Try 57 x 11.

Since 5 + 7 = 12, the answer is:

1

527

627

 

Okay, now it’s your turn. As fast as you can, what is

a.) 83 x 11?   b.) 78 x 11?   c.) 28 x 11?  d.)  63 x 11?


If you got the answer 913,858, 308, 693 respectively then give yourself a pat on the back. You are on your way to become a mathemagician.

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