What is 5/8 of 84?
Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 5/8 of 84? We'll show you a straightforward method to achieve that.
How to calculate 5/8 of 84?
- Multiply the whole number by the numerator of the fraction: 84 × 5 = 420
- Divide this result by denominator of the fraction: 420/8 = 52.5
- Simplify by dividing both the numerator and denominator by their GCD (4):
- 420/4 = 105
- 8/4 = 2
- Which gives: 105/2
Since 105/2 is an improper fraction, the result could also be expressed as a mixed number: 52 1/2
How does it work?
The principle behind finding a fraction of a number, such as 5/8 of 84, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 5/8 of 84)
- Using the cross-multiplication method, multiply both numerators by their opposite denominators:
- Which gives:
- Divide both sides by 8 to isolate x:
- Which gives the result: (or )
Thus, 5/8 of 84 is equal to 105/2 (or 52.5 in its decimal form).