# What is 1/5 of 10?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 1/5 of 10? We'll show you a straightforward method to achieve that.

## How to calculate 1/5 of 10?

- Multiply the whole number by the numerator of the fraction: 10 × 1 = 10
- Divide this result by denominator of the fraction: 10/5 =
**2** - Simplify by dividing both the numerator and denominator by their GCD (5):
- 10/5 = 2
- 5/5 = 1

- Which gives:
**2/1**

## How does it work?

The principle behind finding a fraction of a number, such as 1/5 of 10, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{1}{5}=\frac{x}{10}$ (where `x` represents 1/5 of 10)

- Using the cross-multiplication method, multiply both numerators by their opposite denominators: $1\times 10=5x$
- Which gives: $10=5x$
- Divide both sides by 5 to isolate
`x`: $\frac{10}{5}=\frac{5x}{5}$ - Which gives the result: $\frac{10}{5}=x$ (or $\frac{2}{1}=x$)

Thus, 1/5 of 10 is equal to **2/1** (or 2 in its decimal form).