The same sales, seven pictures
The canteen sold 100 lunches today: 45 pasta bakes, 30 jacket potatoes, 20 fruit pots and 5 salad boxes.
You can show that as a bar chart, a pie chart or a table. Each tells it a different way. Which is best depends on the question.
Key words
| Word | What it means | Example |
|---|---|---|
| Bar chart | Bars whose length shows an amount, one bar for each group. | Lunches sold for each meal |
| Pie chart | A circle cut into slices that show parts of one whole. | Each meal as a slice of 100 lunches |
| Line graph | Points joined by a line to show change over time. | Weekly sales over a term |
| Scatter graph | One dot for each case, to see if two numbers move together. | Temperature against hot meals sold |
| Heat map | A grid where colour or shade shows how big each value is. | Queue size by day and time |
| Flowchart | Boxes and arrows that show the steps of a process. | How an order is made |
| Table | Rows and columns of exact values. | Price of each meal |
| Axis | The line along the edge of a chart that carries the scale and labels. | Days along the bottom |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can say what each of seven techniques shows, and how to create one from data.
Starter: what you already know
Have a go
Starter: what you already know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Compare amounts and parts
A bar chart compares amounts between groups. Bars are easy to compare because your eye judges length well.
A pie chart shows parts of one whole. It works for a few slices. With many slices, a bar chart is clearer.
Show change and links
A line graph puts time along the bottom and joins the points. It shows rises, falls and trends.
A scatter graph has a dot for each case. A rising cloud of dots means two numbers move together. That does not prove one causes the other.
Check: bar, pie, line, scatter
Have a go
Check: bar, pie, line, scatter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.