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0.45 as a fraction

0.45 is 45 hundredths, so write it as 45/100 and simplify to 9/20.

The answer

0.45 = 9/20

How to write 0.45 as a fraction

Put the digits in a place value chart. The last digit tells you the bottom of the fraction.

OnesTenthsHundredths
045

The last digit is in the hundredths column, so 0.45 is 45 hundredths: 45/100.

Simplify by dividing the top and bottom by the same number. In one go, divide by the highest common factor, 5: 45/100 = 9/20.

9 and 20 share no factor except 1, so 9/20 is the simplest form.

As a percentage, 0.45 = 45%: multiply by 100, which moves each digit two places to the left.

To check, divide back: see 9/20 as a decimal and 9/20 as a percentage.

See 9/20

45 squares out of 100 are shaded: 45/100, which is 45%.

More decimals as fractions

Questions parents ask

What is 0.45 as a fraction in its simplest form?

0.45 = 45/100 = 9/20. Divide the top and bottom of 45/100 by 5 to get 9/20.

How do you write 0.45 as a fraction?

The last digit of 0.45 is in the hundredths column, so write the digits over 100: 45/100. Then simplify if you can.

What is 0.45 as a percentage?

0.45 = 45%. Multiply by 100: the digits move two places to the left.

Fractions, decimals and percentages run all through 11+ maths

Converting between them turns up in 11+ questions on percentages, ratio, money and data. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.