What is 3/9 of 19?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 3/9 of 19? We'll show you a straightforward method to achieve that.

How to calculate 3/9 of 19?

  1. Multiply the whole number by the numerator of the fraction: 19 × 3 = 57
  2. Divide this result by denominator of the fraction: 57/9 = 6.3333333333333
  3. Simplify by dividing both the numerator and denominator by their GCD (3):
    • 57/3 = 19
    • 9/3 = 3
  4. Which gives: 19/3

Since 19/3 is an improper fraction, the result could also be expressed as a mixed number: 6 1/3

How does it work?

The principle behind finding a fraction of a number, such as 3/9 of 19, is rooted in the method of cross-multiplication.

Consider the following proportion: 3 9 = x 19 (where x represents 3/9 of 19)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 3 × 19 = 9 x
  2. Which gives: 57 = 9 x
  3. Divide both sides by 9 to isolate x: 57 9 = 9 x 9
  4. Which gives the result: 57 9 = x (or 19 3 = x )

Thus, 3/9 of 19 is equal to 19/3 (or 6.3333333333333 in its decimal form).