Subscribe Feed (RSS)Multiplication Tricks – Multiplying by 11
August 30th, 2009 by Math Tricks | 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: fun math tricks, Math Tricks, math tricks for kids, Multiplication Tricks
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!
That’s really cool! I’m so glad I can help :D
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!
You still have to carry over the remaining digit – in this case ’1′ to give a result of 605.