Statistical Diagrams

Pictograms

Drawing Bar Charts

Drawing Pie Charts

Interpreting Pie Charts

Stem & Leaf Diagrams

Frequency Diagrams and Polygons

Plotting Time Series

Prerequisite Knowledge

• solve comparison, sum and difference problems using information presented in a line graph
• complete, read and interpret information in tables, including timetables.

Success Criteria

interpret and construct

• frequency tables
• bar charts
• pie charts
• pictograms
• pie charts

for categorical data.

• interpret and construct
• vertical line charts for ungrouped discrete numerical data
• tables and line graphs for time series data

and know their appropriate use.

Key Concepts

• Frequency tables must not have overlapping categories
• Diagrams must not imply bias (e.g., equal width bar charts0
• Pictograms need to use suitable symbols to illustrate fractional amounts
• Students need to spend time interpreting the diagrams as well as creating them.

Common Misconceptions

• Bar charts are often drawn with unequal width bars.
• Students often use nonlinear scales for bar and line graphs.
• The frequency is often incorrectly taken as the angle when drawing pie charts.
• Diagrams are often drawn without the correct labels and missing titl