Pie Charts KS2

Help your pupils develop their understanding of pie charts in KS2 with clear explanations, practical teaching ideas and a free ready-to-teach lesson. Pie charts provide a visual way of showing how individual categories make up a whole, making them a useful link between statistics, fractions, percentages and angles.

Children are expected to interpret and construct pie charts in Year 6. They need to understand what each sector represents, calculate values from a chart and use the information to solve problems. Once pupils recognise that the whole circle represents all the data, they can begin to connect each sector with a fraction, percentage, number or angle.

Download a free KS2 Pie Charts lesson for Year 6: 

 

 Download the free lesson

What is a Pie Chart?

A pie chart is a circular diagram used to show how a set of data is divided into different categories. The entire circle represents the whole amount, while each section of the circle represents one category.

The sections of a pie chart are called sectors. A larger sector represents a greater proportion of the data, while a smaller sector represents a smaller proportion.

A complete circle contains 360 degrees. This means that the angle of each sector can be calculated according to the proportion of the total represented by that category.

Introducing Pie Charts in KS2

When introducing pie charts in KS2, it is helpful to begin with familiar fractions of a circle. Children are usually more confident identifying halves, quarters and three-quarters before working with less familiar proportions.

You could begin by showing a circle divided into equal sections and asking questions such as:

• What fraction of the circle is shaded?
• Which sector is the largest?
• Which categories represent equal amounts?
• What percentage of the whole does each sector represent?
• What angle would be needed to draw each sector?

Using simple data based on favourite foods, pets, books, sports or school subjects can make the first examples more accessible. Once children understand the structure of a pie chart, they can move on to charts that require calculations and multi-step reasoning.

Free Pie Charts KS2 Lesson and Worksheets

Looking for free Pie Charts KS2 worksheets and teaching resources? Download this complete lesson from PlanBee's recently updated Charts and Graphs scheme of work.

The free lesson helps children understand how data can be represented in a pie chart. Pupils explore the relationship between the total amount, the proportions shown and the size of each sector.

The lesson includes:

• a detailed lesson plan
• teaching slides for the lesson input
• differentiated Pie Charts KS2 worksheets
• practical and independent activities
• answers and supporting resources

 Download the free lesson

Understanding Pie Charts in KS2

To understand a pie chart, children need to recognise that each sector represents a proportion of the whole. Depending on the question, that proportion may be expressed as a fraction, percentage, decimal, angle or number of items.

Before calculating exact values, encourage pupils to look carefully at the chart and make sensible estimates. They should be able to identify the largest and smallest categories, spot equal sectors and recognise common fractions of a circle.

Reading the title and key

Children should first read the title to establish what the chart represents. They should then look at the labels or key to identify the category represented by each sector.

Identifying the total

Some questions provide the total number represented by the whole pie chart. Pupils can then use the fraction or percentage represented by a sector to calculate the number in that category.

Comparing sectors

Children should compare the relative sizes of sectors before carrying out calculations. For example, a sector representing one-half of the circle must contain twice as much data as a sector representing one-quarter.

Calculating missing information

Pupils may be given some sector values and asked to find a missing amount. Remind them that all sectors together must represent the complete data set and that all the percentages must total 100%.

How to Read a Pie Chart

A useful step-by-step method for reading KS2 pie charts is:

1. Read the title to find out what the chart represents.
2. Check the labels or key to identify each category.
3. Identify the total amount represented by the whole circle.
4. Estimate the fraction or percentage represented by the relevant sector.
5. Use the given information to calculate the exact value.
6. Check that the answer is reasonable in relation to the size of the sector.

Pie Charts, Fractions and Percentages

Understanding pie charts in KS2 depends on children making connections between fractions and percentages. Secure knowledge of common equivalences can make pie chart questions much easier to solve.

• One whole = 100% = 360°
• One-half = 50% = 180°
• One-quarter = 25% = 90°
• Three-quarters = 75% = 270°
• One-fifth = 20% = 72°
• One-tenth = 10% = 36°

Encourage children to look for these familiar proportions before using a written calculation. Recognising that a sector is approximately one-quarter of the circle, for example, can help pupils estimate and check an answer.

How to Calculate Angles for a Pie Chart

To construct a pie chart, pupils must calculate the angle required for each sector. As a full circle contains 360°, the angle for each category depends on its proportion of the total.

The calculation can be completed by dividing the value of the category by the total value and then multiplying the result by 360.

Children should check that all the sector angles total 360°. If the total is not 360°, at least one calculation or measurement is incorrect.

How to Draw a Pie Chart

Drawing accurate KS2 pie charts requires careful calculation and the correct mathematical equipment. Pupils will usually need a pair of compasses, a ruler and a protractor.

1. Organise the data into a table.
2. Calculate the total frequency.
3. Calculate the angle required for each category.
4. Check that the angles total 360°.
5. Use a pair of compasses to draw a circle.
6. Draw a radius from the centre to the edge of the circle.
7. Use a protractor to measure and draw each sector in turn.
8. Label each sector or add a clear key.
9. Add a title explaining what the pie chart represents.

It can be helpful for children to keep a running total of the angles they have drawn. This reduces the risk of measuring each new sector from the wrong starting line.

Solving Problems with KS2 Pie Charts

Once pupils can read and construct pie charts, they should apply their understanding to a range of reasoning and problem-solving questions.

Useful challenges include:

• calculating the value represented by a sector
• finding missing data
• comparing two or more categories
• calculating the difference between categories
• working out the total from the value of one sector
• comparing two pie charts with different totals
• deciding whether a statement about a chart is true or false
• explaining how the chart would change if the total changed

When comparing pie charts, remind children that a larger sector does not always represent a larger number. They must also consider the total amount represented by each chart.

Common Pie Chart Misconceptions

Assuming the largest sector always represents the largest number

This is only true when comparing sectors within the same pie chart. When comparing two different charts, children must take account of the total represented by each one.

Confusing sectors and segments

A sector is the area enclosed by two radii and part of the circumference. A segment is the area between a chord and an arc. The sections used in a pie chart are sectors.

Forgetting that the whole circle represents 360°

All the calculated sector angles must total 360°. This provides a useful way for pupils to check their calculations.

Measuring from the wrong line on a protractor

Children should identify the correct zero line before measuring each angle. It is helpful to estimate whether the angle should be acute, obtuse or reflex before drawing it.

Treating the sector size as the value

A sector shows a proportion rather than necessarily showing the exact number. Pupils may need to use the total represented by the chart to calculate the value.

Pie Charts in the Year 6 National Curriculum

Pie charts are taught explicitly within the Year 6 statistics programme of study. Pupils should learn to interpret and construct pie charts and use them to solve problems.

The curriculum also encourages children to connect their knowledge of angles, fractions and percentages with their interpretation of pie charts. This makes the topic an excellent opportunity to revisit and apply learning from several areas of mathematics.

Before encountering pie charts, children develop their understanding of data through tables, pictograms, bar charts, time graphs and line graphs. Pie charts build on this earlier learning by asking pupils to represent proportional data within a complete circle.

Teach Pie Charts with the Complete Charts and Graphs Scheme

The free Pie Charts lesson comes from PlanBee's recently updated Charts and Graphs scheme of work for Year 6.

The complete scheme helps children become more confident interpreting and presenting data using line graphs, pie charts and graphs involving two variables. Each lesson contains a detailed lesson plan, teaching slides, differentiated activities and printable resources.

View Charts and Graphs

Frequently Asked Questions about Pie Charts KS2