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Math · Grade 3 Math · Unit 3

Unit 3: Wrapping Up Addition and Subtraction within 1,000

Students use place-value understanding to round whole numbers and add and subtract within 1,000. They also represent and solve two-step word problems, using addition, subtraction, and multiplication, and assess the reasonableness of answers.

Worksheets

Every sheet has an answer key. Free to print, no login.

Unit
📝 Worksheet ✅ Answer guide
Concept
Set 1
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Set 2
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Practice
Set 1
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Set 2
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Set 3
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Set 4
📝 Worksheet ✅ Answer key
Advanced
Set 1
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Set 2
📝 Worksheet ✅ Answer key
Set 3
📝 Worksheet ✅ Answer key
Set 4
📝 Worksheet ✅ Answer key

What this unit covers

A Add within 1,000 · 6 lessons
Goals
  • Fluently add within 1,000, using algorithms based on place value and properties of operations.
  • Use place value understanding to compose and decompose numbers.
Lessons
  1. Represent Numbers in Different Ways
  2. Addition and Subtraction Situations
  3. Add Your Way
  4. Introduction to Addition Algorithms
  5. Another Addition Algorithm
  6. Use Strategies and Algorithms to Add
B Subtract within 1,000 · 6 lessons
Goals
  • Fluently subtract within 1,000, using algorithms based on place value, properties of operations, and the relationship between addition and subtraction.
Lessons
  1. Subtract Your Way
  2. Subtraction Algorithms (Part 1)
  3. Subtraction Algorithms (Part 2)
  4. Subtraction Algorithms (Part 3)
  5. Analyze Subtraction Algorithms
  6. Subtract Strategically
C Round within 1,000 · 4 lessons
Goals
  • Round whole numbers to the nearest multiple of 10 and nearest multiple of 100.
Lessons
  1. Multiples of 100
  2. Nearest Multiples of 10 and of 100
  3. Round to the Nearest Ten and the Nearest Hundred
  4. Round and Round Again
D Solve Two-Step Problems · 5 lessons
Goals
  • Assess the reasonableness of answers.
  • Solve two-step word problems, using addition, subtraction, and multiplication.
Lessons
  1. Does It Make Sense?
  2. Diagrams and Equations for Word Problems
  3. Situations and Equations
  4. More Practice to Represent and Solve
  5. Classroom Supplies (Optional)

Helpful to know first

The curriculum says this unit builds on these.

Grade 3 Math · Unit 2 Area and Multiplication
Open unit →
← Unit 2 See the whole map Unit 4 →

Adapted from the Illustrative Mathematics curriculum (v.360), licensed CC BY-NC 4.0. © Illustrative Mathematics.