Picture Graphs & Bar Graphs
A graph turns a pile of numbers into a picture you can understand at a glance. Learn how picture graphs and bar graphs work — titles, keys, and scales — then use them to answer questions like "how many more?" and "how many in all?" Finish by building graphs of your own.
From Data to a Graph
Data is information you collect, usually by counting or measuring. Say a class votes on their favorite fruit. Each vote is one piece of data. You can keep track of the votes with tally marks, then count them up into a table.
| Fruit | Tally | Votes |
|---|---|---|
| Apple | 6 | |
| Banana | 9 | |
| Grapes | 4 | |
| Strawberry | 7 |
A table holds all the numbers, but you have to read every row to compare them. A graph shows the same data as a picture, so you can see right away which fruit won and which one got the fewest votes. The two graphs in this lesson — picture graphs and bar graphs — both work this way.
Picture Graphs
A picture graph uses small pictures to show how many are in each group. Every picture graph has a few important parts:
Tells you what the graph is about.
The groups being counted, listed down the side.
A row of pictures for each category.
Tells you how many each picture stands for. Always read the key first!
Here are the fruit votes as a picture graph. Switch the key and watch what happens — the data stays the same, but the number of pictures changes.
Bar Graphs
A bar graph uses bars instead of pictures. The taller the bar, the bigger the number. Bar graphs have their own set of parts:
Tells you what the graph is about.
Name the categories along the bottom and tell what the numbers on the side mean.
The numbers up the side. They count by the same amount every time — 1s, 2s, 5s, or 10s.
Read a bar by following its top straight across to the scale.
This graph's scale counts by 2s. Tap any bar to read it.
Answering Questions with a Graph
Graphs are made for answering questions. The words in the question tell you what to do with the numbers you read.
Find the tallest bar or longest row — or the shortest. No math needed, just compare.
Read both numbers, then subtract the smaller one from the bigger one. That's the difference.
Read each number the question names, then add them up.
Here are some questions about the Books Read graph in Part 3. (Maya read 12, Leo read 7, Ava read 15, and Sam read 10.)
Practice
Three ways to practice — read graphs, then build them yourself.
Read the Graph
Look closely at the graph — and its key or scale — then answer the question.
Build the Picture Graph
Use the table to build the picture graph. Tap a row or the + button to add, and − to take away. Watch the key!
Build the Bar Graph
Drag each bar up or down until it matches the table. You can also tap a column to jump the bar to that height.