Unit Plan 19 (Grade 5 Math): Measurement Conversions Within a System
5th graders convert between like metric and customary units of length, mass, and volume while solving real-world, multi-step problems. Students use ratio tables and unit reasoning, justify factor choices, and check reasonableness through benchmarks and estimation.
Focus: Convert among like units of length, mass/weight, and volume/capacity within the same measurement system (metric and customary) and solve multi-step word problems with clear units and reasonableness checks.
Grade Level: 5
Subject Area: Mathematics (Measurement & Data)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
Students build practical fluency with 5.MD.1 by moving flexibly among like units (e.g., centimeters to meters, ounces to pounds, cups to quarts) using conversion facts, ratio tables, and unit reasoning. They apply conversions inside multi-step word problems, keeping track of units, estimating with benchmarks, and checking reasonableness.
Essential Questions
- How do I choose and apply a conversion factor to move between like units?
- When should I convert before, during, or after solving a word problem?
- How do benchmarks and units help me decide if an answer is reasonable?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Use conversion factors to convert among like units within metric and customary systems (e.g., cm ↔ m, mL ↔ L, oz ↔ lb, in ↔ ft ↔ yd ↔ mi).
- Represent conversions with ratio tables, unit strips/tape diagrams, and equations; explain why the factor makes sense.
- Solve multi-step word problems that require one or more conversions, maintaining consistent units.
- Use benchmarks and estimation to assess reasonableness of solutions and explain unit choices.
- Communicate solutions clearly with labeled answers and conversion justifications.
Standards Alignment — CCSS Grade 5
- 5.MD.1: Convert among different-sized standard measurement units within a given measurement system and use these conversions in solving multi-step, real-world problems.
- Mathematical Practices emphasized: MP.1 (make sense, persevere), MP.2 (quantitative reasoning), MP.4 (model), MP.5 (tools), MP.6 (precision), MP.7 (structure).
Success Criteria — Student Language
- I can pick the right conversion factor and show how I used it.
- I can keep units consistent and write a labeled answer.
- I can solve a multi-step problem that includes one or more conversions.
- I can explain why my answer is reasonable using benchmarks or an estimate.