Unit Plan 8 (Grade 4 Math): Multi-Step Problems—Choose a Method
Solve multi-step word problems using addition, subtraction, and multiplication; write equations with unknowns, choose efficient strategies, and use estimation and units to check reasonableness.
Focus: Apply addition, subtraction, and multiplication in multi-step contexts; write equations with a letter for the unknown; check units, estimates, and reasonableness.
Grade Level: 4
Subject Area: Mathematics (Operations & Algebraic Thinking • Number & Operations in Base Ten)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
This week trains students to read complex word problems, identify sub-problems, and choose efficient operations. Learners represent steps with tape diagrams/arrays, write an equation with a letter for the unknown, compute accurately, and justify reasonableness with estimation.
Essential Questions
- How do I break a multi-step problem into smaller parts and decide which operation to use first?
- Why is writing an equation with an unknown helpful for organizing a solution?
- How do estimation and units help me check that an answer is reasonable?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Analyze multi-step contexts to sequence operations (add, subtract, multiply) and represent each step.
- Write and solve equations with a letter for the unknown to model problem situations.
- Use tape diagrams, arrays/area models, and number lines to plan and communicate work.
- Apply 4.NBT.4–5 fluencies to compute accurately and check reasonableness with estimation/compatible numbers.
- Explain and defend a strategy, including why the order of steps makes sense and how units are handled.
Standards Alignment — CCSS Grade 4 (spiral across the unit)
- 4.OA.3: Solve multistep word problems posed with whole numbers using the four operations; represent these problems using equations with a letter standing for the unknown quantity; assess the reasonableness of answers using mental computation and estimation strategies including rounding.
- Connections: 4.NBT.4 (fluently add/subtract multi-digit whole numbers), 4.NBT.5 (multiply up to 4-digit × 1-digit and 2-digit × 2-digit using place value and properties).
- Mathematical Practices (MP.1–MP.8) threaded throughout.
Success Criteria — Student Language
- I can plan a multi-step solution, write an equation with an unknown, and explain my steps.
- I can choose an efficient method (add, subtract, multiply) and show a model that matches the story.
- I can use estimation and units to check that my answer is reasonable.