Primary 4 Pie Charts Study Guide
Primary 4 pie charts in four short steps: matching sectors, finding a missing sector, finding the whole from one sector, and finding several parts in order. Every step has a chart to tap through before the worked examples.
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What is a pie chart?
The whole circle is the whole group.
A pie chart shows one complete group, such as 240 cartons of milk. Each sector is one part of that group. The title names the whole and the labels name the parts. A right angle at the centre marks one quarter, and a straight line through the centre marks one half.
In this chapter, your child learns to:
- match each sector to its category, using the title and the labels;
- read a half from a straight line and a quarter from a right angle;
- find a missing sector by subtracting every known part from the whole;
- write a sector as a fraction of the whole, in simplest form;
- find the whole from one known part, then each missing part in order.
Step 1
Reading a pie chart
A bigger count needs a bigger sector. Use the chart title to name the complete group, here 40 pupils. Each sector is one activity. When a chart shows letters instead of names, order the counts: the most pupils fill the biggest sector, and a count that is one quarter of the whole sits in the sector with the right angle.
Tap an activity, then its sector
Activities chosen by 40 pupils
| Activity | Pupils | Sector |
|---|---|---|
| 15 | ? | |
| 6 | ? | |
| 10 | ? | |
| 9 | ? |
In the chart above, how many pupils chose Clay or Drama?
Step 2
Finding a missing sector in a pie chart
Read the half and the quarter, then subtract. A straight line through the centre cuts off half of the circle. A right angle at the centre marks one quarter. Work out those parts from the whole first. The missing sector is what is left after every known part is subtracted, and its fraction is that count over the whole, in simplest form.
Tap Next step
Workshops chosen by 200 pupils
240 cartons of milk were sold. Plain milk is one quarter. 96 were chocolate, 54 were strawberry and the rest were banana. What fraction of the cartons were banana?
Step 3
Finding the total from one sector
Four quarters make the whole. Sometimes the chart gives counts but no total. Match the stated count to its sector first. If that sector has the right angle, it is one quarter, so the whole is 4 times the count. With the whole found, any missing sector is the whole minus every known part.
Tap Next step
Priya's shells: ? altogether
In a pie chart of a class's favourite fruits, the apple sector has a right angle and shows 9 pupils. How many pupils are in the class?
Step 4
Finding missing parts in order
Find the whole first, then each part. A harder chart mixes a marked quarter, a half made of two sectors and a fraction such as 1/12. Every one of these is a part of the same whole, so find the whole first. Then work out each missing part on its own line, and subtract last for the sector that is left.
Tap Next step
Noodle orders at a stall
Curry and tom yam together are half of the orders. How many orders were mushroom?
A pie chart shows 96 drink orders. Hot drinks and juice together are half of the chart. 30 orders were juice. How many were hot drinks?
Primary 4 pie charts questions, worked step by stepCover the working and try each chart question first. Then open a hint, or one line at a time.
A pie chart shows how the 72 pupils in a P4 class travel to school. 30 come by bus, 18 by car and 15 walk. The rest come by MRT. (a) How many pupils come by MRT? (b) What fraction of the class come by MRT? Give your answer in its simplest form.
- MRT = 72 − 30 − 18 − 15 = 9
- fraction by MRT = 9/72
- Divide the numerator and the denominator by 9: 9/72 = 1/8
A pie chart shows the trips chosen by 160 pupils. The zoo sector is half of the chart, and the science centre sector has a right angle. 30 pupils chose the museum and the rest chose the bird park. How many more pupils chose the science centre than the bird park?
- zoo = 160 ÷ 2 = 80
- science centre = 160 ÷ 4 = 40
- bird park = 160 − 80 − 40 − 30 = 10
- 40 − 10 = 30
A pie chart shows the plants in Mrs Lim's garden. The rose sector has a right angle and shows 28 plants. There are 46 orchids and 23 ferns. The rest are herbs. How many herbs are there?
- one quarter = 28
- the whole = 4 × 28 = 112
- herbs = 112 − 28 − 46 − 23 = 15
A pie chart shows how Siti used her pocket money. Food is half of the chart, and she spent $60 on food. Transport is 1/12 of the chart. How much did she spend on transport?
- one half = $60
- all her pocket money = 2 × $60 = $120
- transport = $120 ÷ 12 = $10
A pie chart shows the five kinds of cake a bakery sold. The chocolate sector has a right angle and shows 54 cakes. The pandan and cheese sectors together make half of the chart, and 70 cakes were pandan. Durian cakes were 1/12 of all the cakes. The rest were coffee cakes. How many cheese and coffee cakes were sold altogether?
- the whole = 4 × 54 = 216
- pandan and cheese = 216 ÷ 2 = 108, so cheese = 108 − 70 = 38
- durian = 216 ÷ 12 = 18
- coffee = 216 − 54 − 108 − 18 = 36
- cheese and coffee = 38 + 36 = 74
Step 5
Check yourself
Five short pie chart questions. Nothing is saved, and every reply points to the practice set that fits.
1. A pie chart shows 80 pupils. The football sector is half of the chart. How many pupils chose football?
2. 36 pupils chose a fruit: 18 chose apples, 9 chose pears and the rest chose oranges. What fraction chose oranges?
3. The swimming sector has a right angle and shows 25 pupils. How many pupils are there altogether?
4. Rice is half of a pie chart and shows 70 meals. How many meals does the whole chart show?
5. A pie chart shows 120 pupils. 1/4 chose art, 1/12 chose chess and 50 chose music. The rest chose drama. How many chose drama?
How to use this guide. Before each chart, ask your child what the whole circle stands for and which sector is a half or a quarter. Let the step confirm it. A step takes only a few minutes.
When a total is missing, cover the working and ask which sector the given count belongs to. Your child writes the whole on its own line first, then each missing part, and subtracts for the last sector only at the end.
More study guides
P4 Pie Charts lessons and practice
2 lesson videos and 19 questions across two subtopics, from Basic to Challenge, each with a worked solution.
Watch and practise →