Lesson 7

La suma y la resta en la recta numérica

Lesson Purpose

The purpose of this lesson is for students to attend to the direction of the arrow on the number line to match addition and subtraction expressions.

Lesson Narrative

In previous lessons, students learned that whole numbers can be represented by tick marks and points on the number line. They learned that numbers farther to the right on a number line are greater than those to the left.

In this lesson, students build on that understanding to connect representations that use an arrow to show moving from one number to another on the number line (“jumps”) to the operations of addition and subtraction. Students match equations and number line representations and explain how they know they match (MP2, MP7).

• Engagement
• MLR7

Learning Goals

Teacher Facing

• Recognize that on a number line, jumps to the right represent addition and jumps to the left represent subtraction.

Student Facing

• Emparejemos ecuaciones con representaciones en la recta numérica.

Required Materials

Materials to Gather

Lesson Timeline

 Warm-up 10 min Activity 1 15 min Activity 2 20 min Lesson Synthesis 10 min Cool-down 5 min

Teacher Reflection Questions

How did students work with locating and labeling numbers on the number line prepare them to connect the direction of arrows to addition and subtraction on the number line? What can you do in the next lesson to build on this understanding?

Suggested Centers

• Number Puzzles: Addition and Subtraction (1–4), Stage 4: Within 100 with Composing (Addressing)
• Number Line Scoot (2–3), Stage 1: Twos, Fives, and Tens (Addressing)