Unit Plan 2 (Grade 2 Math): Fluency within 20—Facts, Strategies, and Games
Build addition/subtraction fluency within 20 through make-10, doubles/near-doubles, count on/back, and compensation; students model thinking, choose efficient strategies, and check with inverse or number lines for accurate, confident recall.
Focus: Develop mental strategies (make 10, doubles/near doubles, count on/back, compensation) and work toward instant recall with accuracy and reasoning.
Grade Level: 2
Subject Area: Mathematics (Addition/Subtraction within 20 • Strategy Fluency)
Total Unit Duration: 5 sessions (one week), 35–45 minutes per session
I. Introduction
This week grows efficient, flexible fact thinking. Students learn and practice strategy families (e.g., make 10, doubles/near doubles, count on/back, compensation) using visual models and games. The goal is accurate and increasingly automatic facts within 20 grounded in understanding, not rote speed.
Essential Questions
- How do strategies help me know facts within 20 quickly and accurately?
- When is make 10 better than count on/back (or the other way around)?
- How do I check a fact efficiently (inverse, number line, or model)?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Choose and apply a strategy (make 10, doubles/near doubles, count on/back, compensation) to solve facts within 20.
- Represent and explain strategies with ten-frames, rekenreks, and number lines; write matching equations.
- Use fact families and turnaround facts (commutative thinking) to derive new facts from known ones.
- Monitor accuracy, increase speed appropriately, and use self-checks (inverse or model).
- Describe which strategy they used and why it fits the problem.
Standards Alignment — CCSS Grade 2 (spiral across the unit)
- 2.OA.2: Fluently add and subtract within 20 using mental strategies (e.g., make a ten, decomposing a number leading to a ten, doubles); know from memory all sums of two one-digit numbers by end of Grade 2.
- Mathematical Practices: MP.7 (Look for and make use of structure) and MP.8 (Look for and express regularity) emphasized; MP.1, MP.3, MP.5, MP.6 present through discourse, tools, and precision.
Success Criteria — Student Language
- I can pick a strategy (make 10, doubles, near doubles, count on/back) and tell why I used it.
- I can show my thinking with a ten-frame, rekenrek, or number line and write the equation.
- I can check my answer with the inverse or a quick model and fix mistakes.