Maths
Fractions, decimals and percentages
L . O – To be able to convert between fractions, decimals and
percentages.
Fractions, decimals and percentages are all proportions.It is important to be
able to convert between them.
Converting between Fractions and Decimals.
Example
Write 3/5 as a decimal Simply divide 3 by 5.
(use a calculator if you need to) 3÷5 = 0.6.
Converting from decimals to fraction is a tricky one!
This method only works for terminating decimals (recurring decimals will be
looked at later in this topic).
The denominator will be 10, 100, 1000 etc depending on the number of
decimals places.
Example
Write 0.3 as a fraction.
1. Determine the number of decimal places – there is 1 decimal place here.
2. As there is 1 decimal place, the denominator will be 10.
3. The ‘decimal’ given in the question is then written without.
4. The decimal point as the numerator i.e. 0.3 will be written as 3.
5. This fraction cannot be simplified further therefore the answer is 3/10.
Determine the number of decimal places the number is given toe.g. 0.1 = to 1 dp, 0.35 = 2 dp, 0.657 = 3 dp etc Determine the denominator of the fraction If the number is given to 1 dp à denominator is 10 If the number is given to 2dp à denominator is 100 If the number is given to 3dp à denominator is 1000 etc The ‘decimal’ given in the question is written without the decimal point as the numerator of the fraction. The denominator is the answer to part 2. Simplify the fraction if possible. |
Convert the following fractions into decimals.1. 1/22. 1/3 3. 1/5 4. 3/10 5. 5/8
Convert the following decimals into fractions. 6. 0.85 7. 0.9 8. 0.125 9. 0.25 10. 0.34
Write all fractions in their simplest form! |
Related Topics
Speed-distance-and-time Ratio-and-proportion Decimals-and-fractions