What is 6/8 of 13?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 6/8 of 13? We'll show you a straightforward method to achieve that.

How to calculate 6/8 of 13?

  1. Multiply the whole number by the numerator of the fraction: 13 × 6 = 78
  2. Divide this result by denominator of the fraction: 78/8 = 9.75
  3. Simplify by dividing both the numerator and denominator by their GCD (2):
    • 78/2 = 39
    • 8/2 = 4
  4. Which gives: 39/4

Since 39/4 is an improper fraction, the result could also be expressed as a mixed number: 9 3/4

How does it work?

The principle behind finding a fraction of a number, such as 6/8 of 13, is rooted in the method of cross-multiplication.

Consider the following proportion: 6 8 = x 13 (where x represents 6/8 of 13)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 6 × 13 = 8 x
  2. Which gives: 78 = 8 x
  3. Divide both sides by 8 to isolate x: 78 8 = 8 x 8
  4. Which gives the result: 78 8 = x (or 39 4 = x )

Thus, 6/8 of 13 is equal to 39/4 (or 9.75 in its decimal form).