Key points about conversion of fractions, decimals and percentages
Converting between fractions, decimals and percentages is a useful problem-solving skill.
The data can be more easily ordered by size when written in the same format.
Calculations often give a decimal answer. Converting a decimal to a percentage makes the data easier to understand.
Refresh your knowledge with these guides on equivalent fractions and simplifying fractions.
Check your understanding
How to convert decimals to fractions and percentages
Converting a decimal to a fraction
The final digit’s The value of a digit that relates to its position or place in a number, eg in 1482 the digits represent 1 thousand, 4 hundreds, 8 tens and 2 ones. gives the Number written on the bottom of a fraction. The denominator is the number of equal parts, eg for ⅓, the denominator is 3..
Starting from the first non-zero digit, the digits of the decimal number give the Number written at the top of a fraction. The numerator is the number of parts used, eg for ⅓, the numerator is 1..
The fraction may be simplified when the numerator and denominator have a A whole number which is a factor of two or more numbers. 2, 5 and 10 are common factors of 30 and 20. greater than one.
Converting a decimal to a percentage
Multiply the decimal by 100 to get the percentage value.
Write the percentage value with the percentage symbol (%).
Decimals greater than 1 are greater than 100%.
Follow the working out below
GCSE exam-style questions
- Write the decimal 0·12 as a fraction.
\(\frac{3}{25} \)
The final digit has a hundredths place value, so the denominator is one hundred.
The numerator is 12.
\(\frac{12}{100}\) as a fraction can be simplified to \(\frac{3}{25} \).
- Write the decimal 4·5 as a percentage.
4·5 = 450%
Multiply the decimal by 100 to get the percentage value.
4·5 × 100 = 450
Game - Equivalent fractions and decimals
Practise your equivalent fractions and decimals skills with these puzzles from Divided Islands.
