Idea 19of 22Builds onA line graph shows change over time
Ask questions at three levels
What kinds of questions can a graph answer?
Today you'll discover
- questions answered by one value
- questions that combine values
- questions that need a prediction
Think first“How tall was the plant in week 4?”
Where do you find the answer to this question?
Decide first, then press Next. Ask whether the answer is on the graph, between values, or past it.
A line graph of a bean plant's height, weeks 1 to 6: 2, 3, 7, 9, 11 and 12 cm. First a dashed line reads week 4 at 9 cm. Then a climb from week 1 to week 6 is marked plus 10 cm. Then a dashed line runs on to an empty dot at week 7, labelled about 13 cm. The last step shows walk, bus and car totals with an empty slot for next month.
See the whole ideathe big idea and the key word, in one place
The big idea
First read the data, then read between the data, then read beyond the data.
Three levelsRead the data: one value. Read between the data: combine values. Read beyond the data: predict or decide from them.
Easy to get wrongA prediction is a careful guess, not a fact. Say “about” or “probably”.
Key words
- read the data
- answer a question with one value straight off the graph
- read between the data
- answer a question by combining or comparing values on the graph
- read beyond the data
- answer a question about something not on the graph, by predicting from it
Ready to use it?
- Ask a question at each of the three levels.
- Say which level a question is.