← Back to the activity

Year 8 Maths — Grouped data, histograms and pie charts

Group data into class intervals, read a histogram, and work out the angles in a pie chart.

Name: ________________________

Before you start

This pie chart shows what a class of 40 children picked for their club. Find out what each slice is and how wide its angle is — nothing here is right or wrong.

1234
  1. 1. Reading — 90°, so 10 children
  2. 2. Sport — 90°, so 10 children
  3. 3. Music — 108°, so 12 children
  4. 4. Art — 72°, so 8 children

The four angles add up to 360°, one whole turn. Music is the biggest slice because 12 out of 40 is the biggest share — and 12/40 of 360° really is 108°.

  1. 1.A pie chart shows 200 people. One sector measures 72 degrees. How many people does that sector stand for?

  2. 2.This histogram shows the marks of a class. Tap the interval that holds the most students.

    Write the number of the part.

    1234

  3. 3.These marks are grouped in intervals of 10 starting at 0: 5, 12, 18, 23, 27, 31, 34, 38, 45. How many marks fall in the interval 30 to 40?

  4. 4.What is the main difference between a bar graph and a histogram?

    • a) A histogram has to be drawn in colour
    • b) A histogram has no gaps between its bars, because its classes run on from each other
    • c) A histogram always has more bars than a bar graph
    • d) A bar graph cannot show how many there are of anything

  5. 5.A pie chart is split between 4 subjects with an equal share each. What angle does each sector take, in degrees? Give just the number.

  6. 6.Match each share of the whole to the angle of its sector in a pie chart, in degrees.

    • Half
    • A quarter
    • A third
    • A fifth
    • A tenth
    • 90
    • 120
    • 72
    • 36
    • 180

  7. 7.Put these pie-chart sectors in order by the size of their angle, smallest first.

    • 1/4 of the whole
    • 1/6 of the whole
    • 1/3 of the whole
    • 1/12 of the whole
    • 1/8 of the whole

  8. 8.Sort each mark into the class interval it belongs to.

    Groups: 0 to 20 · 20 to 40 · 40 to 60

    • 41
    • 27
    • 19
    • 8
    • 52
    • 35

Answer key — Year 8 Maths — Grouped data, histograms and pie charts

  1. 1. 40
  2. 2. 2 — 10 to 20 marks — 9 students
  3. 3. 3
  4. 4. b) A histogram has no gaps between its bars, because its classes run on from each other
  5. 5. 90
  6. 6. Half → 180; A quarter → 90; A third → 120; A fifth → 72; A tenth → 36
  7. 7. 1. 1/12 of the whole 2. 1/8 of the whole 3. 1/6 of the whole 4. 1/4 of the whole 5. 1/3 of the whole
  8. 8. 8 → 0 to 20; 35 → 20 to 40; 52 → 40 to 60; 19 → 0 to 20; 41 → 40 to 60; 27 → 20 to 40