Read a Line Graph
A line graph shows how a quantity changes across ordered values, often time. To answer a question, focus on the axes, the scale, and the point or segment being asked about.
1) Read the labels first
- The horizontal axis usually shows the order, such as days, months, or years.
- The vertical axis shows the amount being measured.
- Make sure you know what each unit represents.
2) Find the correct point
- Locate the category or time mentioned in the question.
- Move up or down to the line and read the corresponding value.
- If the graph shows a point between marks, estimate using the scale.
3) Answer exactly what is asked
- Some questions ask for a value at one point.
- Others ask for the change between two points.
- For change, subtract the earlier value from the later value.
- If the question asks for a total over several points, add the relevant values carefully.
4) Simplify the final answer
- Give the number in its simplest form.
- Include units when needed, such as minutes, students, or dollars.
Check your work
Ask yourself: Does the answer match the graph’s scale and the question’s wording? Re-read the axes and make sure you used the correct point or interval.