What is 2/8 of 30?
Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 2/8 of 30? We'll show you a straightforward method to achieve that.
How to calculate 2/8 of 30?
- Multiply the whole number by the numerator of the fraction: 30 × 2 = 60
- Divide this result by denominator of the fraction: 60/8 = 7.5
- Simplify by dividing both the numerator and denominator by their GCD (4):
- 60/4 = 15
- 8/4 = 2
- Which gives: 15/2
Since 15/2 is an improper fraction, the result could also be expressed as a mixed number: 7 1/2
How does it work?
The principle behind finding a fraction of a number, such as 2/8 of 30, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 2/8 of 30)
- 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, 2/8 of 30 is equal to 15/2 (or 7.5 in its decimal form).