Data Handling & Averages

Data handling is about collecting, organising, displaying, and interpreting information. In the GL 11+ exam, you may be asked to read charts and tables, calculate averages, and draw conclusions from data. This lesson covers all the key skills.

---

Types of Data

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

---

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 (how often something occurs).

Pictograms

• Use pictures or symbols to represent data.
• A key tells you what each symbol represents (e.g. one smiley face = 4 people).
• Half a symbol = half the value.

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 measured quantity.

Pie Charts