Creating Double Number Line Diagrams
10 min
Teacher Prep
Setup
Narrative
In this Warm-up, students partition a number line and locate fraction and decimal equivalents in preparation for working with double number lines in this unit. Students are purposely not asked to locate 1 on the number line to see how they reason about locating the 21 and 41. It is important for students to be able to identify the fractions or decimals and label tick marks correctly, interpreting the distance between tick marks rather than the number of tick marks, as the fractional size.
As students discuss with their partner, select students to share their answers to the first question during the whole-class discussion.
Launch
Arrange students in groups of 2. Display the number line for all to see. Give students 2 minutes of quiet think time. Ask students to compare their number line with a partner's number line and to share the fractions or decimals they chose to place on the number line for the second question.
Advances: Reading, Writing
Student Task
Locate and label each number on the number line:
21
41
143
1.5
1.75
Sample Response
Activity Synthesis (Teacher Notes)
Select students to explain how they reasoned about the location of each number on the number line. After each number, ask the class whether they agree or disagree, and if anyone else had a different way of thinking about that number.
If time permits, ask students to locate and label a few more fractions or decimals on the number line.
Anticipated Misconceptions
Students may place 21 in the center of the number line, reasoning that it is half of the number line. Explain to the students that they are placing the number 21, which has a specific value and location on the number line.
10 min
15 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Creating Double Number Line Diagrams
10 min
Teacher Prep
Setup
Narrative
In this Warm-up, students partition a number line and locate fraction and decimal equivalents in preparation for working with double number lines in this unit. Students are purposely not asked to locate 1 on the number line to see how they reason about locating the 21 and 41. It is important for students to be able to identify the fractions or decimals and label tick marks correctly, interpreting the distance between tick marks rather than the number of tick marks, as the fractional size.
As students discuss with their partner, select students to share their answers to the first question during the whole-class discussion.
Launch
Arrange students in groups of 2. Display the number line for all to see. Give students 2 minutes of quiet think time. Ask students to compare their number line with a partner's number line and to share the fractions or decimals they chose to place on the number line for the second question.
Advances: Reading, Writing
Student Task
Locate and label each number on the number line:
21
41
143
1.5
1.75
Sample Response
Activity Synthesis (Teacher Notes)
Select students to explain how they reasoned about the location of each number on the number line. After each number, ask the class whether they agree or disagree, and if anyone else had a different way of thinking about that number.
If time permits, ask students to locate and label a few more fractions or decimals on the number line.
Anticipated Misconceptions
Students may place 21 in the center of the number line, reasoning that it is half of the number line. Explain to the students that they are placing the number 21, which has a specific value and location on the number line.