30% as a fraction
Per cent means out of 100: 30% is 30/100, which simplifies to 3/10.
The answer
30% = 3/10
How to write 30% as a fraction
Per cent means out of 100, so write the percentage over 100: 30% = 30/100.
Simplify by dividing the top and bottom by the same number. In one go, divide by the highest common factor, 10: 30/100 = 3/10.
3 and 10 share no factor except 1, so 3/10 is the simplest form.
As a decimal, 30% = 0.3: divide by 100, which moves each digit two places to the right.
To check, divide back: see 3/10 as a decimal and 3/10 as a percentage.
Using 3/10 to find 30% of an amount
Knowing that 30% is 3/10 makes finding 30% of an amount quick: divide by 10 to find 1/10, then multiply by 3.
30% of 40 = 40 ÷ 10 × 3 = 4 × 3 = 12
The bar model below shows the same steps on 30% of 40. Change the numbers to try your own.
A bar model that finds a percentage of any amount, step by step. 30% of 40 is 12.
See 3/10
More percentages as fractions
Questions parents ask
What is 30% as a fraction?
30% = 30/100 = 3/10 in its simplest form.
What is 30% as a decimal?
30% = 0.3. Divide by 100: the digits move two places to the right.
How do you find 30% of an amount?
30% is 3/10, so divide by 10, then multiply by 3. For 30% of 40: 40 ÷ 10 = 4, and 4 × 3 = 12.
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