Interpret and construct tables, charts and diagrams, including frequency…

The idea

To organise raw data, construct a frequency table by defining categories and using a tally chart to count items in each. For time series data, a table lists values against time points. Different displays suit different data. Bar charts (equal width bars, equal gaps) and pictograms (symbols with a key) show frequencies of categories. Vertical line charts do the same for ungrouped discrete data. Line graphs plot time series data to show trends over time. For a pie chart, the whole circle (360°) is the total. A category's angle is (frequency ÷ total) × 360°. For example, if 7 out of 30 people chose red, the angle is (7/30) × 360° = 84°. Questions require constructing tables, drawing charts accurately, or interpreting them by reading values.

What earns the marks

• A correctly constructed frequency table with accurate tallies and frequencies from raw data.
• Correct calculation of pie chart angles, showing the method (e.g., freq/total × 360).
• Accurately drawn chart with appropriate scales, labels, and keys where needed.
• A correct interpretation that quotes a figure from the display and relates it to the context.

Common mistakes and how to put them right

• Drawing bars of different widths or with no gaps on a bar chart.

• Rounding pie chart angles so the total is not 360°.

• Creating overlapping or non-exhaustive class intervals in a grouped frequency table.

Exam tips

• When creating a frequency table from a list, use a tally system to count accurately.
• Always label your axes and give your chart a title. For pictograms and pie charts, include a key.
• Check that your pie chart angles add up to 360° before you start drawing.