Multiply Up to 20X20 In Your Head
With this trick, you will be able to multiply any two numbers from 11 to 19 in your head quickly, without the use of a calculator. Just follow four simple steps.
I will assume that you know your multiplication table reasonably well up to 10x10.
Try this:
Take 14 x 18 for an example.
Add the first number to the last digit of the second number : 14 + 8 = 22
Multiply the result by 10: 22 x 10 =220
Multiply the last digits of both numbers together: 4 x 8 = 32
Add: 220 + 32 = 252
Another Example
Q. 11 x 14 = ?
Step 1: 11 + 4 = 15
Step 2: 15 x 10 = 150
Step 3: 1 x 4 = 4
Step 4: 150 + 4 = 154
With this trick, you will be able to multiply any two numbers from 11 to 19 in your head quickly, without the use of a calculator. Just follow four simple steps.
I will assume that you know your multiplication table reasonably well up to 10x10.
Try this:
Take 14 x 18 for an example.
Add the first number to the last digit of the second number : 14 + 8 = 22
Multiply the result by 10: 22 x 10 =220
Multiply the last digits of both numbers together: 4 x 8 = 32
Add: 220 + 32 = 252
Another Example
Q. 11 x 14 = ?
Step 1: 11 + 4 = 15
Step 2: 15 x 10 = 150
Step 3: 1 x 4 = 4
Step 4: 150 + 4 = 154
