Unit Plan 3 (Grade 5 Math): Reading, Comparing, and Rounding Decimals
5th graders build deep decimal understanding through reading, writing, comparing, and rounding to thousandths. Students use place-value charts, number lines, and models to justify reasoning, explain magnitude, and choose appropriate precision in real-world contexts.
Focus: Read, write, and compare decimals to thousandths; round to any place using place-value reasoning and models.
Grade Level: 5
Subject Area: Mathematics (Number & Operations in Base Ten — Decimals)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
This week builds decimal sense with multiple representations: base-ten numerals, number names, expanded form, place-value charts, grids, and number lines to thousandths. Students compare decimals using place-value and number-line reasoning and apply rounding flexibly in real contexts (measurement, money, data).
Essential Questions
- How do different representations (expanded form, number line, grid) show the value of a decimal?
- What does it mean to compare decimals accurately and explain why one is greater?
- How does rounding connect to the number line and place value?
- When is rounding useful and when is an exact value necessary?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Read and write decimals to thousandths in base-ten numerals, number names, and expanded form (e.g., 3.047 = 3 + 0.0 + 0.04 + 0.007).
- Compare two decimals to thousandths using place-value and number-line reasoning; record results with >, <, or = and justify.
- Round decimals to any place (tenths, hundredths, thousandths) using benchmark reasoning and number-line models.
- Choose appropriate precision (exact vs rounded) and explain decisions in context.
- Communicate thinking clearly with units, labels, and precise vocabulary.
Standards Alignment — CCSS Grade 5
- 5.NBT.3: Read, write, and compare decimals to thousandths; compare using >, <, = based on meanings of the digits in each place.
- 5.NBT.4: Use place-value understanding to round decimals to any place.
- Mathematical Practices emphasized: MP.1 (make sense), MP.3 (justify/critique), MP.6 (precision), MP.7 (structure), MP.8 (regularity).
Success Criteria — Student Language
- I can write a decimal in numerals, number name, and expanded form and explain what each digit means.
- I can compare decimals to thousandths and justify with a place-value or number-line argument.
- I can round to a given place and explain why the rounded value makes sense.
- I can decide when to use an exact value or a rounded value in a real situation and explain my choice.
- I can show my thinking with clear labels, units, and neat notebook work.