Fastest Method to Multiply any number with 11.

Let’s recall how we used to multiply by 11 in our younger days.

5 4 x 1 1

5  4

5  4  x

5   9   4

However, there’s an easier way to do this. Check this

5  4  x  1  1

5   (5+4)   4

5    9    4

[note style=”” bg=”” border=”” bordercolor=”{{bordercolor}}” color=””] Whenever you multiply an x-digit number by 11, you will always get x+1 digit answer. [/note]

What happened there?

• First digit of 54 became the first digit of answer 594
• Last digit of 54 became the last digit of answer 594
• Middle digit is the sum of surrounding digits 5+4

Lets try our hands on more complex problem.

6 7 x 1 1

6  (6+7)  7

6  13  7?

Remember, the note above, it can be only three digit long. So what happened here? Yes, you got it right, you need to carry “1” of “13” over 6 like this:

6  7  x  1 1

6    13    7

(6+1)   3   7

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7     3    7

 You can apply this trick to more than two digit number. Check out this.

3 2 2 4 x 1 1

3  (3+2)  (2+2)  (2+4)  4

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3   5   4   6   4

I hope you got the point. If not, feel free to comment below. Till we show you another trick, keep practicing. Happy calculating :).