# Lesson 21

Día 4 de centros

### Lesson Purpose

The purpose of this lesson is for students to practice adding and subtracting within 10.

### Lesson Narrative

In Activity 1, students learn a new center called Number Puzzles in which they use number cards to make addition and subtraction equations true. Students build number sense, problem-solving methods, and fluency with addition and subtraction within 10. In Activity 2, students choose from centers previously introduced that focus on adding and subtracting within 10.

• Engagement

### Learning Goals

Teacher Facing

• Add and subtract within 10 in a way that makes sense to them.

### Student Facing

• Juguemos para practicar sumar y restar.

### Required Materials

Materials to Gather

Materials to Copy

• Number Puzzles Addition and Subtraction Stage 1 Gameboard, Spanish
• Number Puzzles Digit Cards

### Required Preparation

Activity 1:

• Create a set of Number Puzzles Cards from the blackline master for each group of 2.

Activity 2:

• Gather materials from previous centers:
• Capture Squares, Stages 1 and 2
• Math Stories, Stage 4
• What's Behind My Back, Stage 2

### Lesson Timeline

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

### Teacher Reflection Questions

Students had many opportunities throughout the unit to practice adding and subtracting within 10. Reflect on the progress students have made in building fluency within 10. Think about ways you can continue this practice by incorporating addition and subtraction into other parts of the school day.