Unit Plan 4 (Grade 6 Math): Constant Speed & Unit Pricing
6th graders apply ratio reasoning to real-life contexts like prices, recipes, and speed. They compute and interpret unit rates using tables and double number lines, make best-buy and constant-speed decisions, and explain reasoning with precise units and clear mathematical communication.
Focus: Solve unit-rate problems (travel, recipes, shopping) and interpret units precisely.
Grade Level: 6
Subject Area: Mathematics (Ratios & Proportional Reasoning)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
This week applies ratio thinking to real decisions: comparing prices by unit price and analyzing constant speed situations. Students represent situations with ratio tables and double number lines, compute unit rates (“per 1”), and use them to make and justify choices. Emphasis: units, reasonableness, and clear language.
Essential Questions
- How does a unit rate help me compare deals and speeds fairly?
- What do the units tell me in miles per hour, dollars per ounce, or cups per serving?
- How can tables and double number lines support solving constant-speed and pricing problems?
II. Objectives and Standards
Learning Objectives — Students will be able to…
- Interpret and compute unit rates in contexts such as pricing, recipes, and speed.
- Use ratio tables and double number lines to solve constant-speed and unit-pricing problems.
- Explain decisions using units and justify with numerical evidence.
- Check answers for reasonableness using estimation and back-checks.
- Communicate solutions in complete sentences with precise unit statements.
Standards Alignment — CCSS Grade 6
- 6.RP.3b: Solve unit rate problems including those involving unit pricing and constant speed.
- 6.RP.2: Understand the concept of a unit rate a/b associated with a ratio a:b (b ≠ 0), and use rate language in context.
- Mathematical Practices emphasized: MP.1 (make sense), MP.3 (justify), MP.4 (model), MP.5 (tools), MP.6 (precision), MP.7 (structure), MP.8 (regularity).
Success Criteria — Student Language
- I can find and say the unit rate with units (for example, dollars per ounce, miles per hour).
- I can use a ratio table or double number line to solve and explain my steps.
- I can make a decision (best buy or faster/slower) and explain why using numbers and units.
- I can estimate first and check if my answer makes sense.
- I can write a clear sentence that answers the question with units.