Representing Fractions on a Line Plot

10 min

Narrative

This Warm-up prompts students to carefully analyze and compare the features of line plots. In making comparisons, students have a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminology students use to talk about the characteristics of line plots with fractional measurements, which students have seen in prior courses. This prepares them to do more arithmetic with fractions, using the data from line plots in the next two lessons.

Launch

  • Groups of 2
  • Display the image.
  • “Pick 3 line plots that go together. Be ready to share why they go together.”
  • 1 minute: quiet think time
Teacher Instructions
  • “Discuss your thinking with your partner.”
  • 2–3 minutes: partner discussion
  • Share and record responses.

Student Task

Which 3 go together?

A
Dot plot from 0 to 4 by 1’s and hash marks at fourths. Beginning at 1, the number of X’s above each half increment is 3, 0, 5, 0, 0, 2.

B

C

D

Sample Response

Sample responses:

A, B, and C go together because:

  • They have data values greater than or equal to 1.

A, B, and D go together because:

  • They have fractional measurements.

A, C, and D go together because:

  • They have different measurements.

B, C, and D go together because:

  • They have titles.
  • They show weight, in pounds.

Synthesis

  • Display Line Plot D.
  • “What does this line plot tell you about the data?” (A total of 8 items were weighed in pounds. All weights were less than 1 pound. Only 1 item weighed half a pound, and 1 item was less than half a pound. Most of the weights were more than half a pound.)
  • If it doesn’t come up in the discussion, ask:
    • “How can we tell which fractions of a pound are shown in the marks of the diagram?” (The number line has 8 partitions, so it’s eighths. Each part represents one-eighth. The data shows 38\frac {3}{8}, 48\frac {4}{8} or 12\frac {1}{2}, 58\frac {5}{8}, 68\frac {6}{8} or 34\frac {3}{4}.)
  • “Today we are going to work with line plots with fractional data and use what we have learned about fractions to solve problems.”
Standards
Building Toward
  • 5.MD.2·Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Use operations on fractions for this grade to solve problems involving information presented in line plots. <em>For example, given different measurements of liquid in identical beakers, find the amount of liquid each beaker would contain if the total amount in all the beakers were redistributed equally.</em>
  • 5.MD.B.2·Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Use operations on fractions for this grade to solve problems involving information presented in line plots. <span>For example, given different measurements of liquid in identical beakers, find the amount of liquid each beaker would contain if the total amount in all the beakers were redistributed equally.</span>

15 min

20 min