Unit Plan 23 (Grade 2 Math): Word-Problem Workshop—All Structures
Solve one- and two-step word problems within 100 by identifying structure and unknowns; model with bar diagrams and number lines, write equations, justify strategies, and check for reasonableness.
Focus: One-/two-step word problems across add to, take from, put together, and compare; unknowns in all positions; choose and justify strategies (drawings, bar models, number lines, equations).
Grade Level: 2
Subject Area: Mathematics (Operations & Algebraic Thinking • NBT • Math Practices)
Total Unit Duration: 5 sessions (one week), 35–45 minutes per session
I. Introduction
Students learn to recognize problem structures, locate the unknown (start/change/result), and choose efficient models and equations to solve. They practice one- and two-step problems and explain why a strategy works, checking for reasonableness (MP.1, MP.4).
Essential Questions
- How do I tell if a problem is add to, take from, put together, or compare?
- Where is the unknown (start, change, or result), and how does that change my equation?
- Which model (drawing, bar model/tape diagram, number line) best fits this problem, and how do I check my answer?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Identify the problem structure and the unknown position.
- Model situations with drawings, bar models, and number lines; write equations with a symbol for the unknown.
- Solve one- and two-step problems within 100/1,000 using place-value strategies (make a ten, add/subtract tens/ones).
- Explain strategy choices and check answers by estimating or using a second method.
- Show precision with units/labels and match models to equations.
Standards Alignment — CCSS Grade 2
- 2.OA.1: Use the four operations to solve word problems within 100, including two-step problems, using drawings and equations with a symbol for the unknown.
- 2.NBT.5: Fluently add and subtract within 100 using place value, properties of operations, and the relationship between addition and subtraction.
- 2.NBT.7: Add and subtract within 1,000 using concrete models or drawings and strategies based on place value and properties.
- Mathematical Practices: MP.1 (Make sense & persevere), MP.4 (Model with mathematics).
Success Criteria — Student Language
- I can name the structure (add to / take from / put together / compare) and find the unknown.
- I can draw a model and write an equation that match the story.
- I can solve, then check with an estimate or a second method, and explain why it works.