A budgeting game for students: plan an event with $100

The event menu and planning rules

The ten-person essentials cost $30 + $10 + $15 = $55, leaving $45 before optional choices. With a $10 reserve, a team may initially spend at most $35 on extras. One valid plan is decorations plus the game kit: $55 + $12 + $18 = $85, leaving $15. There are other valid plans; explain tradeoffs instead of treating one preference as the answer.

How to run the 30-minute activity

1. Minutes 0–5: explain required versus optional costs and model the $55 essentials calculation.
2. Minutes 5–12: teams create their own first plan with a reserve of at least $10. One student checks quantities and another checks the remaining balance.
3. Minutes 12–24: play the six numeric rounds below, two minutes each. Unless a prompt says otherwise, each round starts from the shared $85 example plan; surprise cards do not accumulate.
4. Minutes 24–30: teams apply one chosen surprise to their own plans and justify a revision. Keep that decision exercise on paper so teams may choose different valid solutions.

Six budgeting rounds with worked answers

1. 1. Starting balance

   The shared plan includes essentials, decorations, and the game kit. What remains from $100?

   Host answer and explanation

   $15

   $100 − ($55 + $12 + $18) = $15. The plan meets the initial $10-reserve rule.

2. 2. More guests

   Start again with the $85 plan. Two extra guests attend, each needing a $3 snack and $1 drink. What remains?

   Host answer and explanation

   $7

   Two × ($3 + $1) adds $8. Total spend becomes $93, leaving $7. It is within $100 but below the $10 reserve, so a revision is needed if that rule still applies.

3. 3. Price increase

   Reset to the ten-person $85 plan. Snack portions increase from $3 to $3.50 each. What is the new total spending?

   Host answer and explanation

   $90

   Ten portions each rise by $0.50, adding $5. $85 + $5 = $90, leaving exactly $10.

4. 4. A smaller budget

   Reset to the original $85 plan. The budget is reduced to $80 and the team must still keep $10. What is the minimum spending reduction needed?

   Host answer and explanation

   $15

   The new spending ceiling is $80 − $10 = $70. Reduce $85 by at least $15. Dropping the $18 game kit works; dropping only $12 decorations does not.

5. 5. Compare two revised plans

   Plan A keeps the $55 essentials and $18 game kit. Plan B keeps the essentials, $12 decorations, and ten $1 take-home cards. How much more does Plan B cost?

   Host answer and explanation

   $4

   Plan A costs $73. Plan B costs $77. The difference is $4. Both fit the original $100 budget with a $10 reserve; the group must decide which serves its event better.

6. 6. Spendable money is not the whole balance

   Using Plan A at $73, how much of the $100 budget remains available for extra spending if $10 must stay unspent?

   Host answer and explanation

   $17

   $100 − $73 − $10 = $17. The balance is $27, but only $17 can be spent while preserving the reserve.

Use decisions to check learning

Ask each team to submit its original ledger and one revised ledger. Check four things: required costs are included, quantities match attendees, arithmetic reconciles to the starting budget, and the written explanation names a tradeoff. Give credit for different choices when they satisfy the constraints.

For a shorter lesson, use the menu and rounds 1–3. For a harder lesson, let teams propose a new optional item with an assigned price, then have another team audit the ledger. Keep new costs clearly fictional unless you supply actual dated quotes.

Debrief prompts: Which cost changed with attendance? Which cost was paid once? What did the reserve protect? What information would you need before planning a real event? The goal is explaining a plan, not judging students by personal spending preferences.