The purpose of this activity is for students to generate measurement data and represent the data in a line plot. Students measure pencils in centimeters, check the accuracy of their measurements, and use a template to represent their data in a line plot. In the Synthesis, students revisit the importance of labels on the line plot and also discuss the importance of keeping the Xs the same size and in rows to help make it easier to read the data (MP6).

Pencils are suggested for this activity because the measurements collected are likely to vary. Pencils could be substituted with other classroom items (for example, pipe cleaners, straws, or the sides of books, that might generate interesting measurement data for classroom discussion).

• Share the line plot of a student who wrote a title and labels.
• “Do we know what data _____’s line plot is representing? How do we know?”
• Share a line plot that uses same-size Xs arranged in rows.
• “What do you notice about the Xs in _____’s line plot?”
• “Why is it important to keep the Xs the same size and in rows?” (It can make it look like some measurements have more because the tower looks taller.)
• As needed, draw or display an example of a line plot where the Xs are not in rows (for example, draw different-size Xs and/or draw with a different amount of space above and below each X).

The purpose of this activity is for students to represent measurement data in a line plot with a scale that does not start at 0. In the Launch, students compare line plots that show the same data, but have line plots that start and end with different numbers. They learn that line plots do not have to start with 0, but that the numbers still represent lengths from 0, just like their work with torn tape measures in previous lessons.

When students represent measurement data in their own line plot, they use a template that does not have enough tick marks for students to start at 0 and represent each length in the data table. This encourages students to consider ways to label their line plot without starting at 0. Students may choose to use the least or greatest lengths to decide how to start or end their number line, but they do not need to. The Synthesis discussion will focus on strategies they used to determine how to label, including how they used what they know about a ruler.

This activity uses MLR8 Discussion Supports. Advances: Speaking

• “How is a line plot like a ruler?”
• “How did you decide how to label the numbers on your line plot? How could you revise your line plot so that it represents lengths like a ruler?”

• Show two line plots that use different start and end numbers.
• Consider asking each student:
  • “How did you decide which number to start with?”
  • “How did you use what you know about rulers to label your line plot and place each x?”
• “How are these line plots like a torn tape measure?” (They are missing 0 and some other numbers, but they still show numbers in order. There's still the same length between each number.)