Grocery budget challenge: a $40 class activity for grades 6–8

1. Set the job: "Your team is shopping for three dinners for a family of four. You have $40." Skip sales tax for now; many states don't tax most groceries, and some do.
2. Teams plan the meals before the list. Ask: "What does every dinner need?" Push for a protein, a vegetable or fruit, and a filling side like rice, pasta or bread.
3. Teach unit price in five minutes. Show two sizes of the same item and divide the price by the ounces. Say: "The bigger size is often cheaper per ounce, but not always, and it's only a deal if you'll use it." Many shelf tags show the unit price already.
4. Teams build their list with a price for each item and keep a running total. They round to the nearest dollar to estimate, then add exactly.
5. Halfway through, announce a twist: one item is sold out, or its price went up $3. Teams adjust and write down what they swapped.
6. Each team reports its total, its best swap and one thing it cut. Ask: "What did you give up to stay under $40? That's your opportunity cost."
7. Compare strategies that saved the most: store brands, produce in season, cooking from scratch, planning for leftovers.

Extension: pick one dinner and calculate the cost per serving.

Differentiation: for students who need more support, use a price list with whole-dollar prices, two dinners and a $25 budget. For advanced students, add a dietary need (vegetarian, or a food allergy) or a sales tax rate you choose. For English learners, flyer pictures help; post a word bank: budget, unit price, total, swap, serving. For students with dyscalculia or fine-motor needs, allow a calculator and offer the recorder or shopper role.

Quick check: "Item A is 16 ounces for $3.20. Item B is 24 ounces for $4.32. Which has the lower unit price?" (A is 20 cents an ounce, B is 18 cents, so B.)

If you try it, tell us the lowest total a team reached and what they planned to cook.