Collect and Analyze Data Using Line Plots Unit of Study 4 : Collect and Analyze Data Global Concept Guide: 3 of 3

Content Development  A line plot shows data on a number line.  Students need to know that the numbers below the number line are like the categories in a pictograph or bar graph. However, in a line plot these categories are numerical.  The number of Xs above each number on the number line tells how many times this number or category occurs.  Line plots may be confusing to some students. It is easy to mix up the numbers below the number line and the number of Xs above it.

Content Development Example  In this line plot the numbers on the number line represent the number of letters in a name (numerical category).  Each X stands for one student (or one time each numerical category occurred).

Day 1  The focus of day 1 is relating a line plot to the number line.  Students should begin their work with line plots using a blank number line. As a class you can conduct a survey and display its results on this number line.  Sample Survey Question: How many brothers and sisters do you have?  Each student could be given a post-it note with an x on it and then walk up to the board and place their x above the number of siblings they have.  Discussion should revolve around the parts of a line plot and their purposes (numerical categories, occurrences or Xs, scale, and title.)  Survey Question Non Example: Chose your favorite animal: dog, cat, hamster, rabbit. The survey results from this question SHOULD NOT be displayed on a line plot because the categories (dog, cat, hamster, rabbit) are not numerical.

Day 2  The focus of day 2 is analyzing data in various line plots.  Students should be exposed to many different line plots and questions.  Pay particular attention to the question being asked. Are you asked about the numerical categories or the number of occurrences?

Day 2  Sample Question: What is the difference between the greatest number of letters in a name and the least number of letters in a name?  In this question you are being asked about the range of the numerical categories (numbers at the bottom of a number line). The greatest number of letters in a name is 8 and the least 3. The difference between these categories is 5. (If you 8 and jump back to 3, you will have jumped back 5 times.)  Possible Misconception: Students may misinterpret this question and look for the categories with the most and least amounts of occurrences and find the difference between the occurrences.

Day 2  Another Sample Question : How many students have 5 or more letters in their name?  In this question you are being asked about the students, or the number of occurrences, which are represented by the Xs. Since 5 or more includes numerical categories 5-8, you would have to count all the Xs in each of those numerical categories which would yield an answer of 8 ( ).  Possible Misconception: Students may answer 5 if they misinterpret the meaning of “5 or more.”

Day 3  The focus of day 3 is displaying data in a line plot.  Students should be given opportunities to represent data from frequency tables and tally tables in line plots and compare results.  By the end of Day 3 students should be able to:  Relate line plots to the number line.  Answer questions based on numerical categories or occurrences within a line plot.  Identify the same set of data within multiple representations (tables, chart, and graphs).  Display survey results within a line plot.

Enrich/Reteach/Intervention  Reteach- Have students draw a number line numbered 1 to 6 on a sheet of paper or white board. Have them roll a number cube 5 times, placing a counter above a number each time it is rolled. (Materials: counters, number cubes, paper or white board) Example:  Enrich- Give students a completed line plot and have them create questions for the data displayed. A second option is giving students clues to create a line plot. (Enrich Activity, Ch. 2 TE p. 99B) Ask questions based on results shown in the line plot.