Unit 4, Lesson 7
Addition and Subtraction on the Number Line
Grade 2
Sign in to view assessments and invite other educators
Sign in using your existing Kendall Hunt account. If you don’t have one, create an educator account.
The purpose of this Warm-up is to elicit the idea that addition and subtraction can be represented on the number line. Students have learned that numbers farther to the right are greater and numbers to the left are less. In this Warm-up, students see two number lines with arrows that connect the same numbers. However, one arrow starts at the lesser number and points at the greater number and the other starts with the greater number and points at the lesser number. Noticing the difference in these “jumps” will be useful when students match addition and subtraction equations to representations on number lines in a later activity. While students may notice and wonder many things about these images, it is important to discuss how the arrows represent increases and decreases in value on the number line.
The purpose of this activity is for students to match addition and subtraction equations to number line representations. Some equations use the same numbers, requiring students to look for the direction of the arrow to see if the number line is representing addition or subtraction (MP7). There is one equation that does not have a matching number line representation. Students represent this equation on the last number line.
This last number line can be used as a formative assessment of students' understanding of the connection between equations and their representations on a number line. Teachers can use this information to plan for any additional support that may be needed in the following lesson, where students represent different equations on number lines.
In the Synthesis, students consider how addition and subtraction can look alike on the number line, and how they are different.
Help us improve by sharing suggestions or reporting issues.
Circle the equation each number line represents.