Proper fractions, are fractions where the numerator is smaller than the denominator. For example: $\frac{2}{3}, \frac{4}{9}, \frac{11}{13}…$ are some proper fractions.
Some proper fractions have 2, 4 or 5 as their denominators.
There are certain shortcut methods for converting proper fractions with 2, 4 or 5 as denominators into decimals.
Rules for converting proper fractions with 2, 4 or 5 as denominators into decimals.
At first, we write an equivalent fraction of given proper fraction with a denominator which is a power of ten.
We then shift the decimal to as many places to the left as there are number of zeros after 1 in the denominator.
Convert $\frac{1}{2}$ into a decimal.
Step 1:
$\frac{1}{2}$ is a proper fraction of the type where the denominator is 2,4 or 5.
Step 2:
Here, we write an equivalent fraction of $\frac{1}{2}$ with a denominator 10.
$\frac{1}{2} = \frac{\left ( 1\times 5 \right )}{\left ( 2\times 5 \right )} = \frac{5}{10}$
Step 3:
Shifting the decimal one place to the left we get
$\frac{5}{10} = \frac{5.0}{10} = 0.5$
Step 4:
So, $\frac{1}{2} = 0.5$
Convert $\frac{3}{4}$ into a decimal.
Step 1:
$\frac{3}{4}$ is a proper fraction of the type where the denominator is 2,4 or 5.
Step 2:
We write an equivalent fraction of $\frac{3}{4}$ with a denominator 100.
$\frac{3}{4} = \frac{\left ( 3\times 25 \right )}{\left ( 4\times 25 \right )} = \frac{75}{100}$
Step 3:
Shifting the decimal two places to the left we get
$\frac{75}{100} = \frac{75.0}{100} = 0.75$
Step 4:
So, $\frac{3}{4} = 0.75$
Convert $\frac{2}{5}$ into a decimal.
Step 1:
$\frac{2}{5}$ is a proper fraction of the type where the denominator is 2,4 or 5.
Step 2:
We write an equivalent fraction of $\frac{2}{5}$ with a denominator 10.
$\frac{2}{5} = \frac{\left ( 2\times 2 \right )}{\left ( 5\times 2 \right )} = \frac{4}{10}$
Step 3:
Shifting the decimal one place to the left we get
$\frac{4}{10} = \frac{4.0}{10} = 0.4$
Step 4:
So, $\frac{2}{5} = 0.4$