You are on a mission to stretch every dollar! Compare unit prices, hunt for the best percent-off deal, calculate a restaurant tip, and convert between measurement units — all with real-world rate math.
You have a grocery list and a limited budget. Your job is to be the smartest shopper in the store. Compare package sizes by unit price to find the best buy, figure out which store's sale saves you the most, compute a fair tip at a restaurant, and use rate reasoning to convert measurement units. Fill in every phase, check your answers, and finish with a shopping verdict.
Compare two package sizes of the same product by computing the price per unit for each. The lower unit price is the better buy!
Package A: $3.60 ÷ 12 = $0.30 per unit. Package B: $5.25 ÷ 20 = $0.2625 per unit. Package B has the lower unit price, so it is the better buy even though the package costs more!
Two stores are selling the same item. Each store offers a percent discount. Calculate the final price at each store after the discount to find which one is cheaper.
Store 1: $80 × (1 − 0.25) = $80 × 0.75 = $60.00. Store 2: $75 × (1 − 0.15) = $75 × 0.85 = $63.75. Store 1 ends up cheaper ($60 vs $63.75) even though it started at a higher price!
After shopping you grab a bite to eat. Calculate the tip for the server, then use rate reasoning to convert a measurement unit — a skill smart shoppers use to compare products labeled in different units.
Measurement Conversion (rate reasoning)
Tip: 15% of $20 = $20 × (15 ÷ 100) = $20 × 0.15 = $3.00 tip. Total = $20 + $3 = $23.
Conversion: To convert feet to inches, multiply by the rate (12 inches / 1 foot).
5 feet × (12 inches / 1 foot) = 60 inches. The feet units cancel, leaving inches!
Review your findings and pick the smarter shopping choice, then confirm your unit-rate skills with a quick known-answer problem.
Write a 3–5 sentence shopping verdict that explains your best choices to a friend. Use real numbers from each phase to support your recommendations.
| Category | 4 — Expert | 3 — Proficient | 2 — Developing |
|---|---|---|---|
| Unit Price (6.RP.2/3b) | Both unit prices correct; better buy identified with explanation | Both unit prices correct | One unit price correct or minor division error |
| Percent Discounts (6.RP.3c) | Both store prices correct after discount; cheaper store identified | Both prices correct | One price correct or minor percent error |
| Tip & Conversion (6.RP.3c/3d) | Tip and total correct; conversion uses rate reasoning correctly | Tip and conversion both correct | Tip correct but conversion has an error, or vice versa |
| Communication | Verdict uses all real numbers and justifies every choice clearly | Verdict uses most numbers | Verdict is unclear or missing key numbers |