What is 7/8 of 100?
Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 7/8 of 100? We'll show you a straightforward method to achieve that.
How to calculate 7/8 of 100?
- Multiply the whole number by the numerator of the fraction: 100 × 7 = 700
- Divide this result by denominator of the fraction: 700/8 = 87.5
- Simplify by dividing both the numerator and denominator by their GCD (4):
- 700/4 = 175
- 8/4 = 2
- Which gives: 175/2
Since 175/2 is an improper fraction, the result could also be expressed as a mixed number: 87 1/2
How does it work?
The principle behind finding a fraction of a number, such as 7/8 of 100, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 7/8 of 100)
- 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, 7/8 of 100 is equal to 175/2 (or 87.5 in its decimal form).