Collecting data, scale and line graphs
Tally the answers of a survey, choose a good scale for a graph axis and read a 12-month temperature line graph.
- Iran: grade 7
Guide
This studio follows the Iranian Grade 7 lessons on collecting and displaying data and on graphs. Statistical data is information that has been collected. Statistics is the science of collecting, organising and studying it.
Survey answers start out scattered. A tally table counts them, in groups of five.
For a graph we must choose the scale of the axis ourselves: too fine and the axis gets very long, too coarse and the differences vanish.
A line graph shows how a quantity changes over time. From it we read the highest and lowest values, the biggest change between two neighbouring points, and the mean.