Math activity
Decimal Diner
Play restaurant! Learn about coins and prices by ordering pretend food. Practice counting pennies and understanding that things cost money.
Materials and setup
- play money
- paper for menus
- pencil
- calculator for checking
How this changes by age
Pre-K (ages 3–4)
Play restaurant! Learn about coins and prices by ordering pretend food. Practice counting pennies and understanding that things cost money.
Steps
- Set up a pretend restaurant with play food or pictures of food.
- Price each item using pennies only: an apple costs 5 pennies, a cookie costs 3 pennies.
- Child 'orders' food and counts out the right number of pennies.
- Practice counting pennies up to 10.
- Play both customer and waiter. The waiter counts the pennies to check if it is correct.
- Tell a grown-up one thing that surprised you.
Learning objectives
- Count pennies up to 10 for simple purchases
- Understand that items have prices and you pay with money
- Practice one-to-one counting with coins
Kindergarten (ages 5–6)
Run a pretend diner with prices in dollars and cents. Practice reading prices, counting coins, and making simple purchases with play money.
Steps
- Create a diner menu with 6 items priced from $0.25 to $2.00.
- Give your child play money: dollars, quarters, dimes, nickels, pennies.
- Child orders from the menu and counts out the correct amount.
- Practice reading prices: '$1.50 means one dollar and fifty cents.'
- Challenge: order two items. How much total? Count the money needed.
- Tell a grown-up one thing that surprised you.
Learning objectives
- Read prices written with dollar signs and decimal points
- Count combinations of coins and dollars to match prices
- Add two simple prices together
Early elementary (ages 6–8)
Manage a diner with a full menu. Calculate meal totals, make change, compare prices, and understand decimals as parts of a dollar.
Steps
- Create a detailed menu with at least 10 items, appetizers through desserts, priced from $1.25 to $9.99.
- Order a full meal (3 items) and calculate the total by adding decimals. Line up the decimal points!
- Pay with a $20 bill. Calculate your change by subtracting.
- Compare: which meal combination gives you the most food for under $15?
- Connect to fractions: $0.25 = 1/4 of a dollar, $0.50 = 1/2 dollar, $0.75 = 3/4 dollar.
- Create a tip chart: calculate 10%, 15%, and 20% tips on 4 different meal totals.
- In one sentence, tell a parent or sibling what surprised you today.
Learning objectives
- Add and subtract decimal numbers in money contexts
- Make change by subtracting from whole dollar amounts
- Connect decimal money values to fractions of a dollar
Upper elementary (ages 8–10)
Run a full restaurant business simulation: set menu prices, calculate costs, apply tax and tips, determine profit margins, and analyze which items are most profitable.
Steps
- Design a restaurant menu with 12 items. Set prices based on ingredient costs — real restaurants typically charge 3-4x the ingredient cost (so a $3 ingredient cost becomes a $9-12 menu price). This covers food, staff, rent, and profit.
- Take 5 different orders. Calculate each subtotal, add 8% sales tax, and suggest 18% tip.
- Calculate: if ingredient cost is $3.50 and the menu price is $12.99, what is the profit per item? The profit percentage?
- Analyze: which 3 menu items have the highest profit margin? Create a bar graph comparing profit margins.
- Simulate a busy evening: 15 tables order. Calculate total revenue, total ingredient costs, and net profit for the night.
- Write a business report: is your restaurant profitable? What changes would improve profitability?
- In one sentence, tell a parent or sibling what surprised you today.
Learning objectives
- Calculate sales tax and tips as percentages of decimal amounts
- Determine profit margins using cost and revenue calculations
- Apply multi-step decimal operations in a business context
Safety and evidence note
Read the full activity before beginning. An adult should supervise tools, heat, food, outdoor work, movement, and experiments as appropriate. Completion records that the activity was done; the child’s explanation, work sample, photo, or demonstration is stronger evidence of learning than a completion check alone.
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