We have had several posts regarding lightning speed multiplication and in this post, we are going to learn another trick on how to multiply by 9. Note that this method is only possible if the ones digit is greater than the tens digit.

**How to Multiply 2 Digit Numbers by 9 Fast**

To get the product of 2 digit number multiplied by 9

1.) Copy the tens digit of the 2-digit number as the hundreds digit of the product.

2.) Count the numbers between the the tens and ones digit of the 2-digit number and make it the tens digit of the product.

3.) Count how many numbers from the ones digit of the 2-digit number up to 10 including 10, and then make it the ones digit of the product. Continue reading