# Contents

1. Section A: Add and Subtract Within 20
1. Warm-up: How Many Do You See: Within 10
2. 1.1: Sums I've Got
3. 1.2: Centers: Choice Time
1. Warm-up: Number Talk: Connect Addition and Subtraction
2. 2.1: Cube Tower Addition and Subtraction
3. 2.2: Find the Unknown Number
4. 2.3: Differences I've Got
1. Warm-up: Number Talk: Use Known Sums
2. 3.1: Many Ways to Add and Subtract
2. Section B: Story Problems
1. Warm-up: How Many Do You See: Numbers to 20
2. 4.1: Field Trip to the Aquarium
3. 4.2: Find the Unknown Number
1. Warm-up: True or False: More or Less
2. 5.1: At the Planetarium
3. 5.2: Which Equations Match?
1. Warm-up: Which One Doesnâ€™t Belong: Equations
2. 6.1: The School Carnival
3. 6.2: How Many Rides?
3. Section C: Numbers to 120
1. Warm-up: What Do You Know About 103?
2. 7.2: Count and Represent
3. 7.3: How Many Cats?
1. Warm-up: Estimation Exploration: Tens and Ones
2. 8.3: Centers: Choice Time
1. Warm-up: True or False: Comparison Statements
2. 9.1: A Number Riddle
3. 9.2: More Number Riddles
1. Warm-up: True or False: Add within 100
2. 10.1: Write Number Riddles
3. 10.2: Solve Our Number Riddles
4. Glossary