Home     Wordpress     Codex

Multiplication Tricks – Multiplying by 11

August 30th, 2009 by Steven Pomeroy | Filed under Multiplication Tricks.




One of the easiest multiplication tricks that I know of is also one of the most impressive.  It is the multiplication of two-digit numbers, and, like many other math tricks, there is an easy rule that you can use to solve problems of this sort very quickly in your head.

An Example:

44 x 11

The technique for quickly solving multiplication problems involving any two-digit number by 11 is easy to remember.  Simply add the two digits and insert the result in between the two digit number.

In our example:

44 x 11

4 + 4 = 8, so simply insert “8” between “4” and “4”:

484

So then we have quickly found that
44 x 11 = 484

Now wasn’t that easy?!

Tags: , , ,

4 Responses to “Multiplication Tricks – Multiplying by 11”

  1. Epiphany Luhteran Church & School | 10/03/10

    Hi, I taught this trick to my 5 year old last night and he had a blast showing off to his mother and his older brother. They were both stunned. I’m trying hard to have these boys grow up inspired by math. Thanks for the help!

  2. admin | 10/03/10

    That’s really cool! I’m so glad I can help :D

  3. Joanne | 26/10/11

    Okay. It’s cool. However, what happens when the numbers added equal a two digit number? If you simply followed these instructions 55 X 11 would be 5105, not 605 as it actually is. Clarification is needed!

  4. Math Tricks | 26/10/11

    You still have to carry over the remaining digit – in this case ‘1’ to give a result of 605.

Share Your Thoughts

Prove you are human - or a smart monkey! * Time limit is exhausted. Please reload CAPTCHA.