COMPLEMENT MULTIPLICATION

School children find it difficult to compute or perform the multiplication such as 97 x 95.

In mathematics the term COMPLEMENT is used to perform multiplication.

[Complement of a number is the amount by which that number is less than 100.]

Find 97 x 95.

The complement of 97 is 3. The complement of 95 is 5.

(a) Subtract the complement of one of the numbers from the other number.

97 - 5 = 92 or 95 - 3 = 92.

These are the first two digits of your product.

(b) Multiply the complements of the two numbers. 5 x 3 = 15

These are the last two digits of your final product.

(c) Combine the two numbers to get your answer. 97 x 95 = 9215

This method of shortcut works under one condition.