What is 5/7 of 45?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 5/7 of 45? We'll show you a straightforward method to achieve that.

How to calculate 5/7 of 45?

  1. Multiply the whole number by the numerator of the fraction: 45 × 5 = 225
  2. Divide this result by denominator of the fraction: 225/7 = 32.142857142857

Since 225/7 is an improper fraction, the result could also be expressed as a mixed number: 32 1/7

How does it work?

The principle behind finding a fraction of a number, such as 5/7 of 45, is rooted in the method of cross-multiplication.

Consider the following proportion: 5 7 = x 45 (where x represents 5/7 of 45)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 5 × 45 = 7 x
  2. Which gives: 225 = 7 x
  3. Divide both sides by 7 to isolate x: 225 7 = 7 x 7
  4. Which gives the result: 225 7 = x

Thus, 5/7 of 45 is equal to 225/7 (or 32.142857142857 in its decimal form).