Lesson 4

• Groups of 2
• Display the data and line plot.
• “What do you notice? What do you wonder?”
• 1 minute: quiet think time

• “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

• “How would we adjust the line plot to include a length that is \(6\frac{1}{2}\) inches?” (Add half inch marks to the scale. Partition the inches into two equal parts.)

• Groups of 2
• Display the list and line plot.
• “The list and the line plot both show the heights of seedlings. A seedling is a young plant. Where have you seen seedlings before?” (At the park. In a garden.)
• “Looking at the list, can we tell the height of the shortest seedling?” (Yes, \(\frac{1}{2}\) inch). “What about the tallest seedling?” (Yes, 5 inches)
• “Draw a quick sketch of the shortest seedling and the tallest seedling at their actual heights. Use what you know about the length of an inch.”
• 1 minute: independent work time
• “Share your sketches with your partner.”
• “What else can we tell about the seedlings from looking at the list?” (Twenty-two seedlings were measured. There are two seedlings that are 3 inches tall.)
• 1 minute: partner discussion
• Share responses.

• “Now, take a close look at the line plot. Think about what information we can gather from the line plot and what questions it can help to answer.”
• “Work with your partner to complete these problems.”
• 7–10 minutes: partner work time

• Display the list and the line plot.
• “How is the information displayed in the line plot different from that in the list?” (In the line plot, all the measurements that are the same length are together. The measurements go from smallest to largest along the bottom. In the line plot, we don’t keep writing the numbers over and over, we would just use an x for each measurement.)
• “What were some questions that could be more easily answered with the line plot than the list?” (“How many seedlings were 3 inches tall?” because we could just count the x’s at 3 instead of searching through the list. “What’s the shortest seedling?” because we can find the x on the left end of the scale. “Which seedling height was the most common?” because we can see which number has the most x’s.)

The purpose of this activity is for students to use a line plot to answer questions about a set of length data. The data show measurements to the nearest quarter inch. Students may apply their understanding of fraction equivalence to interpret the data and answer the questions.

• Groups of 2
• “This line plot has data about the lengths of some twigs. What do you notice? What do you wonder?” (Students may notice: The twigs were measured to the nearest quarter inch. The longest twig is \(7\frac{2}{4}\) inches. Students may wonder: Where were the twigs found? How many twigs are shown on the line plot?)

• “Work independently to answer the questions about the data shown in the line plot.”
• 5 minutes: independent work time
• “Work with your partner to finish answering all the questions about the data shown in the line plot.”
• 5–7 minutes: partner work time

• “Discuss with your partner how you answered the last two questions.” (Since the inches are partitioned into 4 equal parts, I knew the scale shows quarters of an inch. I used the quarter inch marks to add an x for a twig that is \(3 \frac {1}{4}\) inches long because that is between 3 and 4 inches.)
• “How did you use fraction equivalence to answer the questions?” (When the question asked how many of the twigs were \(6\frac{1}{2}\) inches long, I used the mark that was at \(6\frac{2}{4}\), because the lengths are equivalent. When I added a twig to the line plot, it was at the \(3\frac{2}{4}\) inch mark, but I wrote \(3\frac{1}{2}\) because the fractions are equivalent.)