Name: ______________________ Date: __________ Partner: ______________________
All prices on this sheet are realistic Long Island supermarket prices for September 2026. Every one is marked [update from this week's circular]; your teacher may write the real price on the board.
The rule
Unit price = price divided by quantity.
Write the dollar sign on every unit price answer. If there is no dollar sign, you divided the wrong way.
The units have to match before you compare. 1 pound (lb) = 16 ounces (oz). To change pounds to ounces, multiply by 16.
Worked example: a 24 oz jar of sauce costs $2.29. $2.29 divided by 24 = $0.095 per oz.
Part A: Find the unit price (round to three decimal places)
| # | Item | Price | Quantity | Unit price (show your division) |
|---|---|---|---|---|
| 1 | Store-brand pasta [update from this week's circular] | $1.29 | 16 oz | $______ per oz |
| 2 | Marinara sauce, jar [update from this week's circular] | $2.29 | 24 oz | $______ per oz |
| 3 | Shredded cheese, bag [update from this week's circular] | $2.49 | 8 oz | $______ per oz |
| 4 | Frozen corn, bag [update from this week's circular] | $1.79 | 12 oz | $______ per oz |
| 5 | Deli half rotisserie chicken [update from this week's circular] | $4.99 | 1 lb 4 oz = ______ oz | $______ per oz |
| 6 | Rice, bag [update from this week's circular] | $2.79 | 2 lb = ______ oz | $______ per oz |
Part B: Which is the better buy per ounce? Circle it and show why.
| # | Option 1 | Option 2 | Unit price 1 | Unit price 2 | Better buy |
|---|---|---|---|---|---|
| 1 | Marinara, 24 oz jar, $2.29 | Marinara, 45 oz jar, $3.79 | $______ per oz | $______ per oz | 24 oz / 45 oz |
| 2 | Name-brand pasta, 12 oz box, $1.49 | Store-brand pasta, 16 oz box, $1.29 | $______ per oz | $______ per oz | name / store |
| 3 | Shredded cheese, 8 oz bag, $2.49 | Shredded cheese, 2 lb bag, $7.99 | $______ per oz | $______ per oz | 8 oz / 2 lb |
Part C: Sales tax on non-food items
Copy the rule from the board:
In New York, most grocery food is ______ taxed. Non-food items (foil, paper plates, cups, soap) and candy, soda, and prepared hot food ______ taxed. The rate in our county is about ______ percent. [Sal: confirm the local rate]
Circle the items that get taxed at the register: a bag of rice, a roll of foil, a two-liter soda, paper plates, a loaf of bread, a candy bar.
A roll of foil costs $3.49. The tax at 8.625 percent is $______. The total for the foil is $______.
Part D: The bulk trap
A 10 lb bag of potatoes costs $5.99. A 3 lb bag costs $2.99.
Unit price of the 10 lb bag: $______ per lb. Unit price of the 3 lb bag: $______ per lb. Cheaper per pound: ______.
This family eats potatoes about twice a month, about 2 pounds each time. Potatoes keep for two to three weeks in a cool, dark place, and this family keeps them in a warm kitchen cabinet.
Which bag should this family buy? ______
Why? Use the sentence starter: "The big bag is cheaper per ____________, but this family should buy the ____________ because ____________."
Part E: When cheaper is not better (copy the list from the debrief)
Cheaper per unit is the wrong buy when:
- ____________________
- ____________________
- ____________________
- ____________________
- ____________________
One of my own from home: ____________________
Teacher key
Part A: 1. $0.081 per oz. 2. $0.095 per oz. 3. $0.311 per oz. 4. $0.149 per oz. 5. 20 oz; $0.250 per oz. 6. 32 oz; $0.087 per oz. Accept answers within $0.002.
Part B: 1. $0.095 vs $0.084; the 45 oz jar. 2. $0.124 vs $0.081; store brand. 3. $0.311 vs $0.250; the 2 lb bag (then ask: can the family use 2 lb of cheese before it molds? That is Part D's question).
Part C: most grocery food is not taxed; non-food items, candy, soda, and prepared hot food are taxed; about 8.625 percent in Suffolk and Nassau counties [Sal: confirm]. Taxed: foil, soda, paper plates, candy bar. Not taxed: rice, bread. Foil tax: $3.49 times 0.08625 = $0.30 (rounded). Total $3.79.
Part D: 10 lb bag: $0.599 per lb. 3 lb bag: $0.997 per lb. Cheaper per pound: the 10 lb bag. The family should buy the 3 lb bag: they use about 4 lb a month, the potatoes will sprout or rot in a warm cabinet before they use 10 lb, and the waste costs more than the savings. Accept the 10 lb bag only with a fix (a cool, dark place to store them and a plan to use them within three weeks).
Part E (from the debrief): it will spoil before you use it; there is no room to store it; the family will not eat that much; a food rule or allergy rules it out; you cannot afford the bigger total today even though it is cheaper per ounce.