What is 10/4 of 42?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 10/4 of 42? We'll show you a straightforward method to achieve that.

How to calculate 10/4 of 42?

  1. Multiply the whole number by the numerator of the fraction: 42 × 10 = 420
  2. Divide this result by denominator of the fraction: 420/4 = 105
  3. Simplify by dividing both the numerator and denominator by their GCD (4):
    • 420/4 = 105
    • 4/4 = 1
  4. Which gives: 105/1

How does it work?

The principle behind finding a fraction of a number, such as 10/4 of 42, is rooted in the method of cross-multiplication.

Consider the following proportion: 10 4 = x 42 (where x represents 10/4 of 42)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 10 × 42 = 4 x
  2. Which gives: 420 = 4 x
  3. Divide both sides by 4 to isolate x: 420 4 = 4 x 4
  4. Which gives the result: 420 4 = x (or 105 1 = x )

Thus, 10/4 of 42 is equal to 105/1 (or 105 in its decimal form).