Understanding Line Plots

What is a Line Plot?

A line plot is a simple way to show data. It uses a number line and marks each piece of data with an $X$ above the number. Line plots make it easy to see how often a certain measurement or value happens.

How to Read a Line Plot

To read a line plot, you just look at the numbers on the bottom line and count the $X$s stacked above them. Each $X$ stands for one person, item, or measurement.

Example: Imagine a line plot showing the lengths of different pencils in inches. If you want to answer, "How many pencils measured $6$ inches?", you find the number $6$ on the number line and count the $X$s above it. If there are $4$ $X$s, then $4$ pencils are $6$ inches long.

How to Make a Line Plot

Let's create a line plot together using this list of shoe sizes: $5, 6, 5, 7, 6, 5, 8$

Step 1: Draw a number line. Look at your data. The smallest shoe size is $5$ and the largest is $8$. Draw a number line that includes all the numbers from $5$ to $8$ (so $5, 6, 7, 8$).

Step 2: Mark your data with an $X$. Go through your list of shoe sizes one by one. Every time you see a number, draw one $X$ above that number on your line.

• Size 5: There are three $5$s in the list, so draw three $X$s stacked above the $5$.
• Size 6: There are two $6$s, so draw two $X$s stacked above the $6$.
• Size 7: There is one $7$, so draw one $X$ above the $7$.
• Size 8: There is one $8$, so draw one $X$ above the $8$.

When you are done, the tallest stack of $X$s will be above the number $5$. This quickly tells you that size $5$ is the most common shoe size in your group!