Unit Plan 35 (Grade 3 Math): NBT Power-Up—Rounding, +/– within 1,000, × by 10s
Strengthen Grade 3 place-value skills by rounding to the nearest 10/100, adding and subtracting within 1,000, and multiplying by multiples of 10 using efficient, pattern-based strategies and reasonableness checks.
Focus: Targeted practice to polish rounding, addition/subtraction within 1,000, and multiplying by multiples of 10 using place-value structure and efficient strategies.
Grade Level: 3
Subject Area: Mathematics (Number & Operations in Base Ten)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
Students consolidate place-value understanding to round numbers, choose and justify efficient strategies for addition/subtraction within 1,000, and use patterns to multiply by multiples of 10 (10–90). Emphasis is on structure (MP.7), reasonableness, and clear explanations.
Essential Questions
- How does place-value structure help me round and compute accurately?
- When should I estimate (round first) and when should I compute exactly?
- How do patterns with zeros and place-value shifts make multiplying by multiples of 10 efficient?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Round whole numbers to the nearest 10 or 100 and explain decisions using number lines.
- Fluently add/subtract within 1,000 using place-value strategies, properties, and/or the standard algorithm, with reasonableness checks.
- Multiply a one-digit number by a multiple of 10 (10–90) by recognizing place-value patterns and shifts.
- Select and justify efficient methods (decomposing, compensation, algorithm, open number line) and communicate steps precisely.
Standards Alignment — CCSS Grade 3
- 3.NBT.1: Use place value to round whole numbers to the nearest 10 or 100.
- 3.NBT.2: Fluently add and subtract within 1,000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.
- 3.NBT.3: Multiply one-digit whole numbers by multiples of 10 in the range 10–90 using strategies based on place value and properties of operations.
- Mathematical Practices: MP.7 (look for and make use of structure) emphasized; MP.1, MP.2, MP.6 support.
Success Criteria — Student Language
- I can round to the nearest 10/100 and explain my choice with a number line or benchmark.
- I can add/subtract within 1,000 and check that my answer is reasonable.
- I can multiply by multiples of 10 by using patterns and place-value shifts.
- I can tell why my strategy is efficient and show each step clearly.