# Lesson 7

Día 1 de centros (optional)

### Lesson Purpose

The purpose of this lesson is for students to work with place value and practice addition and subtraction 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 stage 2 of the Mystery Number center, which was first introduced in grade 1. In this new stage, called Three-digit Numbers, they use clues based on place value to identify the number being described. In Activity 2, students choose to continue working on Mystery Number, or choose between two previously introduced centers focused on addition and subtraction.

### Learning Goals

Teacher Facing

• Practice addition and subtraction within 100.
• Use place value to describe and identify a number.

### Student Facing

• Usemos el valor posicional para identificar números y practiquemos la suma y la resta.

### Required Materials

Materials to Gather

Materials to Copy

• Mystery Number Stage 2 Directions, Spanish

### Required Preparation

Activity 2:

Gather materials from:

• Jump the Line, Stage 1
• Mystery Number, Stage 2
• Number Puzzles, Stages 24

Building Towards

### Lesson Timeline

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

### Teacher Reflection Questions

Who got to do math today in class and how do you know? Identify the norms or routines that allowed those students to engage in mathematics. How can you adjust these norms and routines so all students do math tomorrow?