# Lesson 13

Día 2 de centros (optional)

### Lesson Purpose

The purpose of this lesson is for students to practice estimating and measuring lengths and adding and subtracting within 100.

### Lesson Narrative

This lesson is optional because it is an opportunity for extra practice that not all classes may need. In Activity 1, students learn a new center, Target Measurements. In this center, students practice estimating and measuring length in inches and centimeters. In Activity 2, students can choose to continue working on Target Measurements, or choose between a previously introduced center and a new stage of the Number Puzzles center, In this stage, called Within 100 with Composing, students work with sums and differences within 100 with composing and decomposing a ten.

### Learning Goals

Teacher Facing

• Determine the unknown number that makes an equation true.
• Estimate and measure objects.

### Student Facing

• Completemos ecuaciones y sigamos estimando y midiendo.

### Required Materials

Materials to Gather

Materials to Copy

• Number Puzzles Digit Cards
• Target Measurement Stage 1 Recording Sheet, Spanish
• Number Puzzles Addition Stage 4 Gameboard, Spanish

### Required Preparation

Activity 2:

Gather materials from:

• Number Puzzles, Stages 4
• Estimate and Measure, Stage 2
• Target Measurements, Stage 1

### Lesson Timeline

 Warm-up 10 min Activity 1 15 min Activity 2 25 min Lesson Synthesis 10 min

### Teacher Reflection Questions

As students worked in their centers today, whose ideas were heard, valued, and accepted? How can you use what you learned today about your students to inform how you will use centers in the future?