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Grade 3 Mathematics

Multi-Digit Addition & Subtraction

Build procedural fluency with adding and subtracting numbers up to 10,000. Master regrouping, estimation, and checking your work!

FL B.E.S.T. Standard: MA.3.NSO.2.1

Addition with Regrouping

Add multi-digit numbers, regrouping when sums exceed 9

Subtraction with Regrouping

Subtract with regrouping, including across zeros

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Estimation

Use rounding to estimate and check answers

Procedural Fluency

Solve accurately and efficiently using any standard algorithm

Key Concepts Covered

Standard Algorithm

Any efficient and accurate procedure for adding/subtracting. Students should explain WHY it works using place value.

Regrouping

Trading 10 ones for 1 ten, or 10 tens for 1 hundred. Key phrase: "10 of this = 1 of that."

Subtracting Across Zeros

When there's a zero, regroup from the next place. Example: 500 becomes 4 hundreds + 10 tens.

Checking Reasonableness

Estimate first, then compute. If your answer is way off from the estimate, check your work!

Teacher Guide

Complete lesson plans and strategies

  • Standard breakdown with clarifications
  • Common misconceptions and fixes
  • Multiple algorithm options
  • 5-day lesson sequence
  • Differentiation strategies
View Guide

Student Concept Worksheet

Introduction to addition and subtraction concepts

  • Step-by-step examples with regrouping
  • Place value reminders
  • Estimation strategies
  • 5 guided practice problems
View Worksheet

Practice Worksheet

25 problems across all skill types

  • Vertical addition (6 problems)
  • Vertical subtraction (6 problems)
  • Horizontal format (4 problems)
  • Subtraction with zeros (4 problems)
  • Word problems (5 problems)
View Practice

FAST Practice Quiz

10 test-format questions

  • Multiple choice questions
  • Fill-in-the-blank problems
  • Error analysis questions
  • Multi-step word problems
View Quiz

Parent Activity Guide

Home practice activities

  • Receipt math challenge
  • Road trip mileage tracker
  • Game night score keeper
  • Conversation starters
  • Spanish summary included
View Activity

Answer Keys

Complete solutions with explanations

  • All worksheet answers
  • Quiz answer explanations
  • Scoring guide
  • Common error analysis
View Answers