What is 9/10 of 9?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 9/10 of 9? We'll show you a straightforward method to achieve that.

How to calculate 9/10 of 9?

  1. Multiply the whole number by the numerator of the fraction: 9 × 9 = 81
  2. Divide this result by denominator of the fraction: 81/10 = 8.1

Since 81/10 is an improper fraction, the result could also be expressed as a mixed number: 8 1/10

How does it work?

The principle behind finding a fraction of a number, such as 9/10 of 9, is rooted in the method of cross-multiplication.

Consider the following proportion: 9 10 = x 9 (where x represents 9/10 of 9)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 9 × 9 = 10 x
  2. Which gives: 81 = 10 x
  3. Divide both sides by 10 to isolate x: 81 10 = 10 x 10
  4. Which gives the result: 81 10 = x

Thus, 9/10 of 9 is equal to 81/10 (or 8.1 in its decimal form).