Home

Maths

Ratio and proportion

Calculating percentages of amounts

Calculating percentages of amounts

Videos

Summary

Exercises

Select Lesson

Algebra

Simple formulae

Linear number sequences

Missing number problems

Solving equations with two unknowns

Ratio and proportion

Solving ratio problems

Calculating percentages of amounts

Scale factor problems

Unequal sharing

Statistics

Pie charts

Line graphs

Discrete and continuous data

Mean, median, mode and range

Geometry - position and direction

Coordinate polygons

Drawing and reflecting shapes on the coordinate grid

Drawing and translating shapes on the coordinate grid

Describing positions in the four quadrants

Geometry - properties of shapes

2D shapes: Types and properties

3D shapes: Types and properties

Comparing and classifying shapes

3D shape nets

Geometric shapes: Types and properties

Parts of a circle

Drawing and measuring angles with a protractor

Angles around a point and on a straight line

Finding missing angles

Measurement

Calculate and convert between units of measure

Perimeter of composite rectilinear shapes

Area of irregular shapes

Area of parallelograms and triangles

Formulae for the area and volume of shapes

Calculating the volume of cubes and cuboids

Fractions

Finding fractions of amounts

Mixed numbers and improper fractions

Comparing and ordering fractions greater than 1

Simplifying fractions

Add and subtract fractions: Different denominators

Multiplying pairs of proper fractions

Dividing fractions by whole numbers

Equivalent fractions, decimals and percentages

Multiplying decimals by whole numbers

Dividing and expressing the answer as a decimal

Multiplication and division

Times tables up to 12 x 12

Multiplying a 4-digit number by a 1 or 2-digit number

Dividing numbers up to 4 digits by a 2-digit number

Mental maths strategies

Common factors and multiples

Order of operations: BIDMAS

Using estimation to check answers

Addition and subtraction

Adding numbers using mental maths

Using column addition to add numbers

Subtracting numbers using mental maths

Using column subtraction to subtract numbers

Multi-step problems with addition and subtraction

Inverse operations to check calculations

Number and place value

Numbers to 10,000,000

Place value: Four-digit numbers

Representing numbers in different ways

Rounding any number up to 1,000,000

Counting using positive and negative numbers

Counting in powers of 10

Negative numbers

Explainer Video

Tutor: Alice

Summary

Calculating percentages of amounts

​​In a nutshell

It is often useful to calculate percentages of amounts when solving problems. Some are simple and some require a little more work.


Finding percentages of amounts

There are two methods to calculating percentages of amounts: by using simple percentages that you already know, or by converting the percentage to a fraction and multiplying.


Method 1: Using simple percentages

You can always split up a percentage into smaller simple ones. Below are some simple percentages that you need to remember how to calculate, as well as their equivalent fraction pairs.

PERCENTAGE

FRACTION

HOW TO CALCULATE

50%50 \%50%​​

​12\frac{1}{2}21​​​

Divide by two

​25%25\%25%​​

​14\frac{1}{4}41​​​

Divide by four

​10%10\%10%​​

​110\frac{1}{10}101​​​

Divide by ten

​5%5\%5%​​

​120\frac{1}{20}201​​​

Divide by ten and then two

​1%1\%1%​​

​1100\frac{1}{100}1001​​​

Divide by one hundred



Example 1

In a sale, everything is 17%17\%17% off. What saving would be made on £200£200£200?​


Split 17%17\%17% into simple percentages.

17%=10%+5%+1%+1%17\%=10\%+5\%+1\%+1\%17%=10%+5%+1%+1%


Work out each of the simple percentages.

10%10\% 10% of 200=200÷10=20200 = 200\div10=20 200=200÷10=20

5%5\% 5% of 200=10%÷2=20÷2=10200= 10\% \div 2=20\div2=10200=10%÷2=20÷2=10

1%1\% 1% of 200=200÷100=2200= 200\div100=2200=200÷100=2

​​​

Add together the simple percentages.

20+10+2+2=£32‾20+10+2+2=\underline{£32}20+10+2+2=£32​



Method 2: Turn into a fraction and multiply

The second method is to simply turn the percentage into a fraction and multiply by the amount. Remember that to convert from a percentage to a fraction you take the percentage as a fraction out of one hundred.


Example 2

Calculate 29%29\%29% of £3300£3300£3300.


Write 29%29\%29% as a fraction out of one hundred.

29100\frac{29}{100}10029​​​


Multiply by £3300£3300£3300.

29100×£3300=£3300÷100×29=£33×29=£957‾\begin{aligned}\frac{29}{100}\times£3300=£3300 \div 100 \times 29\\=£33 \times 29 = \underline{£957} \end{aligned}10029​×£3300=£3300÷100×29=£33×29=£957​​​

Read more

Learn with Basics

Learn the basics with theory units and practise what you learned with exercise sets!
Length:
Equivalent fractions, decimals and percentages

Unit 1

Equivalent fractions, decimals and percentages

Percentages as fractions and decimals

Unit 2

Percentages as fractions and decimals

Jump Ahead

Score 80% to jump directly to the final unit.

Optional

Calculating percentages of amounts

Unit 3

Calculating percentages of amounts

Final Test

Test reviewing all units to claim a reward planet.

Create an account to complete the exercises

FAQs - Frequently Asked Questions

How do I work out a percentage using fractions?

Turn the percentage into a fraction and multiply by the amount. To convert from a percentage to a fraction you take the percentage as a fraction out of one hundred.

How do I work out 1% of a number?

To work out 1% of a number, divide by one hundred.

How do I work out 10% of a number?

To work out 10% of a number, divide by ten.

How do I work out 50% of a number?

To work out 50% of a number, divide by two.

How do I find a percentage of an amount?

There are two methods to calculating percentages of amounts: by using simple percentages that you already know, or by converting the percentage to a fraction and multiplying.

©2020 - 2024 evulpo AG

Beta