What is 5/7 of 66?

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 66? We'll show you a straightforward method to achieve that.

How to calculate 5/7 of 66?

  1. Multiply the whole number by the numerator of the fraction: 66 × 5 = 330
  2. Divide this result by denominator of the fraction: 330/7 = 47.142857142857

Since 330/7 is an improper fraction, the result could also be expressed as a mixed number: 47 1/7

How does it work?

The principle behind finding a fraction of a number, such as 5/7 of 66, is rooted in the method of cross-multiplication.

Consider the following proportion: 5 7 = x 66 (where x represents 5/7 of 66)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 5 × 66 = 7 x
  2. Which gives: 330 = 7 x
  3. Divide both sides by 7 to isolate x: 330 7 = 7 x 7
  4. Which gives the result: 330 7 = x

Thus, 5/7 of 66 is equal to 330/7 (or 47.142857142857 in its decimal form).