What is 9/8 of 38?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 9/8 of 38? We'll show you a straightforward method to achieve that.

How to calculate 9/8 of 38?

  1. Multiply the whole number by the numerator of the fraction: 38 × 9 = 342
  2. Divide this result by denominator of the fraction: 342/8 = 42.75
  3. Simplify by dividing both the numerator and denominator by their GCD (2):
    • 342/2 = 171
    • 8/2 = 4
  4. Which gives: 171/4

Since 171/4 is an improper fraction, the result could also be expressed as a mixed number: 42 3/4

How does it work?

The principle behind finding a fraction of a number, such as 9/8 of 38, is rooted in the method of cross-multiplication.

Consider the following proportion: 9 8 = x 38 (where x represents 9/8 of 38)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 9 × 38 = 8 x
  2. Which gives: 342 = 8 x
  3. Divide both sides by 8 to isolate x: 342 8 = 8 x 8
  4. Which gives the result: 342 8 = x (or 171 4 = x )

Thus, 9/8 of 38 is equal to 171/4 (or 42.75 in its decimal form).