What is 7/8 of 82?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 7/8 of 82? We'll show you a straightforward method to achieve that.

How to calculate 7/8 of 82?

  1. Multiply the whole number by the numerator of the fraction: 82 × 7 = 574
  2. Divide this result by denominator of the fraction: 574/8 = 71.75
  3. Simplify by dividing both the numerator and denominator by their GCD (2):
    • 574/2 = 287
    • 8/2 = 4
  4. Which gives: 287/4

Since 287/4 is an improper fraction, the result could also be expressed as a mixed number: 71 3/4

How does it work?

The principle behind finding a fraction of a number, such as 7/8 of 82, is rooted in the method of cross-multiplication.

Consider the following proportion: 7 8 = x 82 (where x represents 7/8 of 82)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 7 × 82 = 8 x
  2. Which gives: 574 = 8 x
  3. Divide both sides by 8 to isolate x: 574 8 = 8 x 8
  4. Which gives the result: 574 8 = x (or 287 4 = x )

Thus, 7/8 of 82 is equal to 287/4 (or 71.75 in its decimal form).