# Contents

1. Section A: Add and Subtract within 1,000 without Composition or Decomposition
1. Warm-up: Number Talk: Count Back
2. 1.1: Notice the Difference
3. 1.2: What’s the Big Difference?
1. Warm-up: Number Talk: Add Multiples of 10
2. 2.1: Show It with Base-ten Blocks
3. 2.2: How Many with Base-ten Blocks and Equations
1. Warm-up: Number Talk: Tens and Hundreds
2. 3.1: Jump Back, Back, Back
3. 3.2: Who Spilled Paint?
1. Warm-up: Number Talk: Count Back by Place
2. 4.1: Zero Tens and Zero Ones
3. 4.2: Add or Subtract with Expanded Form
4. Section A Summary
1. Warm-up: How Many Do You See: Hundreds, Tens, and Ones
2. 5.2: Centers: Choice Time
3. Section A Practice Problems
2. Section B: Add within 1,000 using Place Value Strategies
1. Warm-up: Number Talk: Numbers that Make 10
2. 6.1: Add Two-digit and Three-digit Numbers
3. 6.2: Card Sort: Perfect Ten
1. Warm-up: How Many Do You See: Are They the Same?
2. 7.1: Compose a Ten or a Hundred
1. Warm-up: How Many Do You See: Too Many Tens
2. 8.1: Compare the Sums
3. 8.2: Different Ways to Show Your Thinking
1. Warm-up: Number Talk: Ten and Some More
2. 9.1: How Did You Add Three-digit Numbers?
1. Warm-up: Number Talk: Use Sums to Find Sums
2. 10.1: Card Sort: Three-digit Sums
3. 10.2: Find the Unknown Value
4. Section B Summary
1. Warm-up: Number Talk: Make 100
2. 11.2: Introduce Five in a Row, Add Within 1,000 with Composing
3. Section B Practice Problems
3. Section C: Subtract within 1,000 using Place Value Strategies
1. Warm-up: What Do You Know About 354?
2. 12.1: Subtract from 354
3. 12.2: Decompose with Base-ten Blocks
1. Warm-up: Which One Doesn’t Belong: Blocks and Blocks
2. 13.1: Subtract with Base-ten Diagrams
3. 13.2: Decompose a Ten or Hundred
1. Warm-up: Which One Doesn’t Belong: Blocks and Blocks and Blocks
2. 14.1: Agree to Disagree
3. 14.2: Sort and Subtract
1. 15.1: Elena’s Thinking
2. 15.2: Walk About and Subtract
1. Warm-up: True or False: Equations Based on Place Value
3. 16.2: Find It Your Way
4. Section C Summary
1. Warm-up: Number Talk: Simplify It
2. 17.2: More Target Numbers and Choice Time
1. Warm-up: Number Talk: Subtract within 1,000
2. 18.1: Student Population
4. Section C Practice Problems
4. Glossary