# Lesson 13

Center Day 3

### Lesson Purpose

The purpose of this lesson is for students to practice adding 2 two-digit numbers with composing a ten.

### Lesson Narrative

In each activity, a new stage of a center is offered as a choice as students choose from previously introduced centers. All of the centers focus on working with two-digit numbers.

Teacher Facing

### Student Facing

• Let’s add 2 two-digit numbers.

### Required Materials

Materials to Gather

Materials to Copy

• Five in a Row Addition and Subtraction Stage 6 Gameboard
• Target Numbers Stage 3 Recording Sheet

### Required Preparation

Activity 1:

• Gather materials form previous centers:
• Target Numbers, Stages 1-2
• Number Puzzles, Stages 1-4
• Mystery Number, Stage 1

Activity 2:

• Gather materials from previous centers:
• Five in a Row, Stages 1-6
• Get Your Numbers in Order, Stage 1
• Grab and Count, Stage 2

### Lesson Timeline

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

### Teacher Reflection Questions

As students worked in centers today, whose ideas were heard, valued, and accepted? How can you adjust the group structure for your next center day, to ensure each student’s ideas are heard?