Solve Problems Using Graphs

Graph problems may need more than one calculation.

The scale turns pictures into real amounts.

Read it: Read a bar graph with a scale

On this graph each grid line counts 10 birds. Jays' bar stops halfway between 20 and 30, so Jays is 25.

1. Find what each grid line counts: here, 10.
2. Follow the top of a bar across to the scale and count up by 10s.
3. A bar that stops halfway between two lines is half of 10 more: 20 and 5 make 25.

A scale that counts by 10s fits big numbers on a short graph: 60 birds is only 6 grid lines.

Every grid line counts the same, so a taller bar still means more.

To draw a bar, count up by the scale's number and stop at the line for that number: Robins' bar stops at 40.

Count up the scale by its number, not by ones, to read or draw a bar.

On a graph that counts by 5s, one bar reaches 45 and another reaches 30. How many more does the first bar show? — 15. 45 − 30 = 15.