Unit Plan 9 (Grade 1 Math): Addition within 20—Making Ten

Focus: Use ten frames and number bonds to compose/decompose numbers within 20, emphasizing make ten strategies and explanations.

Grade Level: 1

Subject Area: Mathematics (Operations & Algebraic Thinking)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session

I. Introduction

Students build fluency within 20 by using ten frames and number bonds to make ten, then add the rest (e.g., 9 + 6 → 9 + 1 + 5 → 10 + 5). They connect models to equations, use the commutative and associative properties informally, and justify their strategy choices.

Essential Questions

• How does making ten help me add quickly and accurately?
• How can number bonds and ten frames show how I decompose and compose numbers?
• When is it useful to reorder or regroup addends (properties) to make a problem easier?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Use ten frames and number bonds to break apart an addend and make ten, then add within 20.
2. Represent thinking with drawings, counters, and equations; read/record solutions precisely.
3. Apply commutative (a + b = b + a) and associative reasoning informally to create easier sums.
4. Explain and compare strategies; check for reasonableness by relating addition to counting on.

Standards Alignment — CCSS Grade 1 (threaded across the unit)

• 1.OA.3: Apply properties of operations (commutative/associative) as strategies to add.
• 1.OA.4: Understand subtraction as an unknown-addend problem (bridge-to-10 links).
• 1.OA.5–6: Relate counting to addition; add/subtract within 20 using strategies such as making ten, decomposing, doubles/near doubles.
• Mathematical Practices: MP.2 (Reason abstractly & quantitatively), MP.8 (Look for regularity in repeated reasoning) emphasized; MP.6 threaded.

Success Criteria — Student Language

• I can make ten with a ten frame, then add the rest to find a total within 20.
• I can show my thinking with a number bond and equation, and explain why it works.
• I can use turn-around facts (commutative) or regroup addends (associative idea) to make a problem easier.