Study guide: Build and Read Whole-Unit Data Displays
Use picture graphs, bar graphs, whole-unit line plots, and category comparisons.
Ideas to explain in your own words
- A picture graph uses repeated symbols to represent a count.
- A bar graph’s labeled scale connects its length to a count.
- A line plot keeps repeated observations.
- A category display can support more than one calculation.
Useful vocabulary
- bar graph
- A display whose bar length represents a category count.
- line plot
- A number line with a mark for every observation.
Watch your reasoning
- Do not assume a symbol is a physical item rather than a recorded response.
- Bar width is not the recorded count.
- Stack height counts frequency, not measured length.
- Do not extend a small fictional record to everybody’s preferences.
A worked review example
The key says one star means one vote. The bike row has five stars, so it records five votes. Five stars are not five bikes owned unless the graph’s question says that; its stated measured quantity is votes. Read what the symbols count as well as their value. Do not assume a symbol is a physical item rather than a recorded response. Draw a key and a row containing the stated number of symbols.
Make a practice plan
- Read a Picture Graph with a One-Item Key: A one-vote key with seven circles shows 7 votes.
- Read Bar Height from a Whole-Number Scale: Bars end at 9 and 4 on the same scale. Expected difference: 5 responses.
- Represent Each Measurement on a Line Plot: Plot 6,6,7,8,8 cm. Expected stacks: two at 6, one at 7, two at 8.
- Combine and Compare Category Records: For red 8, green 5, blue 6 responses, red plus blue is 14 and red minus green is 3.