There is a trick to multiplying lots of numbers, even numbers that are greater than ten. The example we are going to be talking about today is multiplying by 11. 11 has it's own special multiplication trick because it is just two ones and anything times one is itself. I will tell you all about it!
ISAIAH LOPEZ
Ok, so this trick breaks up into two parts, the first part is multiplying 11 by numbers one to 9. They are just that number doubled. 9x11=99, 2x11=22, 4x11=44, etc. You can do that for any single digit natural number. It will be that number doubled. Once you get to ten, things go a little differently. Well, more like once you get to eleven because anything times ten is just itself with a zero after it (10x11=110).
When things get to two digit numbers, what you have to start doing is a little trick that involves basic addition of numbers. When you multiply a two-digit number by eleven, you add its two digits and put the sum of them in the middle. For example 32x11=352 because 32 consists of the digits 3 and 2. 3+2=5 so you put the digit 5 in the middle. The final product is 352.