# Lesson 4

Midamos y ubiquemos

### Lesson Purpose

The purpose of this lesson is for students to add and subtract within 20. Students measure lengths of objects and represent measurement data in line plots and answer questions about the data.

### Lesson Narrative

In this lesson, students continue to practice fluency with addition and subtraction within 20 with an emphasis on knowing from memory single-digit addition facts. Students revisit line plots, which they worked with in a previous unit. They measure the length of objects and use measurement data to create line plots.

• Action and Expression
• MLR2

### Learning Goals

Teacher Facing

• Fluently add and subtract within 20.
• Measure lengths in centimeters.
• Represent measurement data in a line plot.

### Student Facing

• Hagamos diagramas de puntos, y sumemos y restemos medidas de longitud.

### Required Materials

Materials to Gather

### Required Preparation

Activity 1:

• Each students needs an unsharpened pencil.
• The activity works best if it is likely that students will have a range of pencil lengths between and among groups. If necessary, sharpen pencils to different lengths and distribute them randomly to students.

### Lesson Timeline

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

### Teacher Reflection Questions

Reflect on the development of students’ fluency with addition and subtraction within 20. What activities or discussions particularly helped students during the year? What will you do differently next year to foster your students’ fluency with addition and subtraction?