What is 4/5 of 65?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 4/5 of 65? We'll show you a straightforward method to achieve that.

How to calculate 4/5 of 65?

  1. Multiply the whole number by the numerator of the fraction: 65 × 4 = 260
  2. Divide this result by denominator of the fraction: 260/5 = 52
  3. Simplify by dividing both the numerator and denominator by their GCD (5):
    • 260/5 = 52
    • 5/5 = 1
  4. Which gives: 52/1

How does it work?

The principle behind finding a fraction of a number, such as 4/5 of 65, is rooted in the method of cross-multiplication.

Consider the following proportion: 4 5 = x 65 (where x represents 4/5 of 65)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 4 × 65 = 5 x
  2. Which gives: 260 = 5 x
  3. Divide both sides by 5 to isolate x: 260 5 = 5 x 5
  4. Which gives the result: 260 5 = x (or 52 1 = x )

Thus, 4/5 of 65 is equal to 52/1 (or 52 in its decimal form).