• Fluently add multi-digit whole numbers using the standard algorithm(4.NBT.B.4)
• Use estimation to check reasonableness of sums
• Apply addition to real-world contexts

• Place value charts (1 per student)
• Whiteboards and markers (1 set per student)
• Addition problem cards (1 set per pair)

Practice estimating sums before calculating

• Display: 3,847 + 2,165. Estimate first!
• Strategies: Round to nearest thousand (4,000 + 2,000 = 6,000)
• Or round to nearest hundred (3,800 + 2,200 = 6,000)
• Actual sum: 6,012. Our estimate was very close!

Reinforce algorithm with larger numbers

• Review place value alignment - ones under ones, etc.
• Add 45,678 + 23,456 step by step
• Emphasize regrouping at each place as needed
• Add three or more addends: 1,234 + 2,345 + 3,456
• Strategy: Add in pairs, then combine
• Use estimation to verify answers are reasonable

Build fluency through structured practice

• Timed practice: 5 problems in 5 minutes
• Partner checking: Trade papers and verify
• Discussion: What strategies help you add quickly AND accurately?
• Practice adding three 4-digit numbers

Independent fluency practice

• Complete 8-10 multi-digit addition problems
• Estimate before calculating at least 3 problems
• Word problems involving addition of large numbers
• Challenge: Find the missing addend: ____ + 4,567 = 8,234

• What helps you avoid careless mistakes?
• Why is estimation important even when we can calculate exactly?
• Exit ticket: 56,789 + 34,211 = ?