What is 1/10 of 21?
Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 1/10 of 21? We'll show you a straightforward method to achieve that.
How to calculate 1/10 of 21?
- Multiply the whole number by the numerator of the fraction: 21 × 1 = 21
- Divide this result by denominator of the fraction: 21/10 = 2.1
Since 21/10 is an improper fraction, the result could also be expressed as a mixed number: 2 1/10
How does it work?
The principle behind finding a fraction of a number, such as 1/10 of 21, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 1/10 of 21)
- Using the cross-multiplication method, multiply both numerators by their opposite denominators:
- Which gives:
- Divide both sides by 10 to isolate x:
- Which gives the result:
Thus, 1/10 of 21 is equal to 21/10 (or 2.1 in its decimal form).