Data Handling and Averages

Data handling questions on the CSSE 11+ maths paper test your ability to read, interpret, and analyse data from charts, tables, and graphs. You also need to calculate averages (mean, median, mode) and understand the range. The CSSE often combines data skills with reasoning — for example, asking you to compare two data sets or explain which average is most appropriate.

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Types of Data

Type	Description	Examples
Discrete	Can only take particular values (usually whole numbers)	Number of pets, shoe size, goals scored
Continuous	Can take any value within a range	Height, weight, time, temperature

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Types of Charts and Graphs

Bar Charts

• Used for discrete or categorical data.
• Bars have equal widths and gaps between them.
• The height of each bar shows the frequency.

Line Graphs

• Used to show how data changes over time.
• Points are plotted and joined with straight lines.
• The x-axis usually shows time; the y-axis shows the quantity measured.

Pie Charts