40% as a fraction
Per cent means out of 100: 40% is 40/100, which simplifies to 2/5.
The answer
40% = 2/5
How to write 40% as a fraction
Per cent means out of 100, so write the percentage over 100: 40% = 40/100.
Simplify by dividing the top and bottom by the same number. In one go, divide by the highest common factor, 20: 40/100 = 2/5.
If you cannot spot 20, smaller steps get there too:
- Divide by 10: 4/10
- Divide by 2: 2/5
2 and 5 share no factor except 1, so 2/5 is the simplest form.
As a decimal, 40% = 0.4: divide by 100, which moves each digit two places to the right.
To check, divide back: see 2/5 as a decimal and 2/5 as a percentage.
Using 2/5 to find 40% of an amount
Knowing that 40% is 2/5 makes finding 40% of an amount quick: divide by 5 to find 1/5, then multiply by 2.
40% of 40 = 40 ÷ 5 × 2 = 8 × 2 = 16
The bar model below opens on 40% of 40 and reaches the same answer another way, by working out 10% as 40 ÷ 10, then 40% as 4 × 10%. Change the numbers to try your own.
A bar model that finds a percentage of any amount, step by step. 40% of 40 is 16.
See 2/5
More percentages as fractions
Questions parents ask
What is 40% as a fraction?
40% = 40/100 = 2/5 in its simplest form.
What is 40% as a decimal?
40% = 0.4. Divide by 100: the digits move two places to the right.
How do you find 40% of an amount?
40% is 2/5, so divide by 5, then multiply by 2. For 40% of 40: 40 ÷ 5 = 8, and 8 × 2 = 16.
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