Line plots, step by step

A line plot puts measurements on a number line and stacks an X above each one.

The question
Length of our pencils (inches)
34567

How many more pencils measured 5 inches than 3½ inches?

Length of our pencils (inches)

along the bottom:inches
each mark:one pencil
3 inches:2 pencils
3½ inches:1 pencils
4½ inches:2 pencils
5 inches:4 pencils
5½ inches:2 pencils
6 inches:3 pencils
6½ inches:3 pencils
7 inches:2 pencils
3 inches:2 pencils
3½ inches:1 pencils
4½ inches:2 pencils
5 inches:4 pencils
5½ inches:2 pencils
6 inches:3 pencils
6½ inches:3 pencils
7 inches:2 pencils
3
  1. A line plot is not bars to read off a scale — each mark is one pencil. So the number ALONG the bottom and the number of marks ABOVE it are two different quantities, and the question wants one of them.
  2. Counting the stacks: 2 at 3, 1 at 3½, 2 at 4½, 4 at 5, 2 at 5½, 3 at 6, 3 at 6½, 2 at 7.
  3. 4 at 5 inches, 1 at 3½ inches: 4 − 1 = 3 — so the answer is 3.

How it works.

  1. 01

    A line plot is not bars to read off a scale — each mark is one pencil. So the number ALONG the bottom and the number of marks ABOVE it are two different quantities, and the question wants one of them.

  2. 02

    Counting the stacks: 2 at 3, 1 at 3½, 2 at 4½, 4 at 5, 2 at 5½, 3 at 6, 3 at 6½, 2 at 7.

  3. 03

    4 at 5 inches, 1 at 3½ inches: 4 − 1 = 3 — so the answer is 3.