What you need to know

Things to remember:

• To convert a fraction into a decimal, we turn the fraction into a division question.
• If you learn some basic fractions with 1 on top, you can then just multiply this decimal by the actual number on top.

Remember, a fraction is just another way of writing a division.

$$\frac{1}{4}=1\div4$$

But we know how to do divisions; we use the bust stop method!

So, we have divided our 1 by 4, to get 0.25. This means that:

$$\frac{1}{4}=0.25$$

We can use this method to write every fraction as a decimal, but it is easier to try and learn some of the common fractions and decimals.

Fraction                             Decimal

$\dfrac{1}{2}$                                       0.5

$\dfrac{1}{4}$                                       0.25

$\dfrac{1}{5}$                                       0.2

$\dfrac{1}{8}$                                       0.125

$\dfrac{1}{10}$                                     0.10

$\dfrac{1}{20}$                                     0.05

$\dfrac{1}{50}$                                     0.02

$\dfrac{1}{100}$                                   0.01

When you learn these, all you will have to do is multiply to find bigger fractions.

What is $\dfrac{3}{8}$ as a decimal?

How would we say this fraction in words? We’d say “three-eighths”. So, this is telling us that we have three lots of one-eighth.

$$\frac{3}{8}=3\times\frac{1}{8}$$

But, we can write $\dfrac{1}{8}$ as a decimal.

$$\frac{1}{8}=0.125$$

$$\frac{3}{8}=3\times\frac{1}{8}=3\times0.125=0.375$$

$$\frac{3}{8} =0.375$$

Let’s break this down into steps.

What is $\dfrac{3}{4}$ as a decimal?

Step 1: Think of the fraction with a 1 on top and write this as a decimal.

$$\frac{1}{4}=0.25$$

Step 2: Multiply by the actual number on top of the fraction.

$$0.25\times3=0.75$$

$$\frac{3}{4}=0.75$$

Example Questions

Question 1: What is $\dfrac{2}{5}$ as a decimal?

Step 1: Think of the fraction with a 1 on top and write this as a decimal.

$$\frac{1}{5}=0.2$$

Step 2: Multiply by the actual number on top of the fraction.

$$0.2\times2=0.4$$

$$\frac{2}{5}=0.4$$

Question 2: What is $\dfrac{7}{10}$ as a decimal?

Step 1: Think of the fraction with a 1 on top and write this as a decimal.

$$\frac{1}{10}=0.1$$

Step 2: Multiply by the actual number on top of the fraction.

$$0.1\times7=0.7$$

$$\frac{1}{10}=0.7$$