Skill: Interpret line graphs

To interpret a line graph:

1. Read the horizontal axis to find the category or time.
2. Read the vertical axis to see what is being measured and how the scale is counted.
3. Find the plotted point above the category or time.
4. Compare points to describe increases, decreases, equal values, or the greatest value.
5. Remember that connected points show the measurements in order.

Example: A line graph shows the number of books Maya read over four months.

• The horizontal axis shows: January, February, March, and April.
• The vertical axis shows the number of books. Its labels are $(0, 2, 4, 6,)$ and $8$, so each interval represents $2$ books.
• The points are:
  • January: $2$ books
  • February: $4$ books
  • March: $4$ books
  • April: $8$ books

Question: How many more books did Maya read in April than in January?

Find the April value: $8$ books.

Find the January value: $2$ books.

Subtract:

$$8-2=6$$

Maya read 6 more books in April than in January.

The graph also shows that the number of books increased from January to February, stayed the same from February to March, and increased again from March to April. April was the month with the greatest value.