# Math Trick Multiplying by 11 Quickly and Easily

Learn two simple Math tricks that will help you multiply 11 faster than a calculator.

Let's first multiply 11 by a two digit number.

11 x 45

1. Split the number  4         5
2. Add the two numbers 4 + 5 = 9
3. The 9 goes between the two split numbers 495
4. 11 x 45 = 495

11 x 21

1. Split the number 1      2
2. Add the two numbers1 + 2 = 3
3. Place the total of adding between the two numbers 132
4. 11 x 21 = 132

11 x 99

1. Split 9    9
2. Add 9 + 9 = 18
3. This time we need to carry ten to the first number 9 + 10 = 19 then place the 8 and the other split number.
4 11 x 99 =  1089

Now let's look at larger numbers.

5434 x 11

1. The first number will be 5 and the last digit will be 4    5         4

2. 5434 add the last digit and the number to it's left.  4 + 3 = 7
3. so now you have 5   75
4. Add 3 and the number to the left 3 + 4 = 7    now you have 5 775
5. Add 4 and the number to it's left 4 + 5 = 9
6. So now you have 59,775 which is the answer.

The video works several more examples if you are confused.