Sheet № 184 · Foundation + Higher · AQA · Edexcel · OCR
Reading and Drawing Bar Charts –
Bar charts are one of the most common ways to display data in GCSE Maths and appear on Foundation and Higher papers across AQA, Edexcel and OCR. You need to know how to read values from bar charts, draw them accurately, and recognise dual and composite bar charts. At Higher level, you may also be asked to identify misleading features. Thi
§Key definitions
Question:
A shop records the number of each type of drink sold in a day: Tea 35, Coffee 50, Juice 20, Water 30. Draw a bar chart.
Answer:
The bar chart should have four bars at heights 35, 50, 20 and 30, with labelled axes and a title.
(a)
English difference: 22 − 15 = 7. History: 18 − 14 = 4. Art: 20 − 10 = 10. Art has the biggest difference.
(b)
Art total = 10 + 20 = 30 pupils.
Q1 (Foundation):
A bar chart shows goals scored by four teams: Team A = 12, Team B = 8, Team C = 15, Team D = 10. Which team scored the most goals?
§Formulas to memorise
Frequency = height of the bar read from the vertical axis
Single bar chart — one bar per category, used to display one data set.
Dual (comparative) bar chart — two bars side by side for each category, used to compare two data sets.
Composite (stacked) bar chart — bars divided into sections stacked on top of each other, showing how each category is made up of sub-categories.
Draw each bar to the correct height. Keep all bars the same width with equal gaps between them.
Worked example
A shop records the number of each type of drink sold in a day: Tea 35, Coffee 50, Juice 20, Water 30. Draw a bar chart.
Working:
⚠ Common mistakes
- ✗Unequal bar widths or gaps. All bars should be the same width with equal spacing.
- ✗Missing labels or title. Always label both axes and include a title — missing labels lose marks.
- ✗Poor scale choice. If your scale is too compressed or too stretched, the chart becomes hard to read. Choose round-number intervals (5, 10, 20, etc.).
- ✗Misreading composite bars. For a stacked section, read only the height of that section, not the total from the bottom.
✦ Exam tips
- →Use a ruler and sharp pencil to draw neat, accurate bars.
- →If the question says "draw an accurate bar chart", your bars must reach the exact correct height — careless drawing loses accuracy marks.
- →For dual bar charts, always include a key to distinguish the two data sets.
- →When asked about misleading graphs, check whether the axis starts at zero, whether bar widths are equal, and whether the scale is consistent.
- →For related data display, see drawing pie charts. For key formulas, visit our GCSE Maths formulas page.