Six workshop attendees become eighteen: check your supplies cost

You have prepared supply kits for six workshop attendees. Then twelve more sign up. How many kits do you need, and what happens to the cost? This small fictional exercise gives you a prompt for an answer with an adjustable headcount. You can check every total without AI.

What OpenAI announced

On October 7, 2026, OpenAI introduced Intelligent UI in ChatGPT: answers with interactive elements. Its example shows a guest-count control and a shopping list. That is the vendor’s example, not our test. We wrote the workshop prompt below as a separate exercise; we have not run it in ChatGPT.

One kit per person, one fixed cost

Imagine one supply kit costing EUR 4 per attendee and EUR 20 of shared materials. These are invented amounts for an exercise, not a workshop offer. Let n be the headcount: kits = n and total = 4 × n + 20 EUR. Only whole numbers from 0 to 20 are allowed. At n = 0, the fixed EUR 20 cost remains.

Copy the prompt and keep the checking table

Create a simple interactive supplies calculator for a fictional workshop directly in your answer. The attendee count n must be a whole number from 0 to 20, starting at 6. Each attendee needs one kit costing EUR 4, plus a fixed EUR 20 for shared materials. Show kits = n, the formula total = 4 × n + 20, and the currency EUR. Add a labeled headcount control; update both the kit count and total when it changes. Reject negative numbers, fractions, non-numeric or blank input, and values above 20 with an explanation; do not round or silently adjust them. For invalid input, do not display a new valid total, and clearly mark any previous result as out of date. If an interactive answer is unavailable, return a static table for n = 0, 1, 6, 12, 18, 20 with kit count, calculation, and total in EUR. I do not need bookings, payments, or personal data.

Expected results you can check independently

These are the calculated expected values for our exercise, not ChatGPT output. For six people: 4 × 6 + 20 = EUR 44. For eighteen: 4 × 18 + 20 = EUR 92. Twelve extra kits therefore add EUR 48; the fixed cost stays the same.

Before relying on the calculator

• Try 6, 12, and 18 in turn: expect EUR 44, 68, and 92. Then check the boundaries: 0 → 20, 1 → 24, and 20 → 100 EUR.
• Enter −1, 2.5, text, a blank field, and 21. Each should produce a clear error, rather than rounding or a new valid result.
• Check that changing 6 to 18 updates both kits and cost, with EUR and the formula still visible. Missing controls or a wrong answer mean the prompt has not yet been fulfilled.

A useful fallback without controls

Use the table above, or substitute your own whole-number n from 0 to 20 into 4 × n + 20. For example, nine people need nine kits: 36 + 20 = EUR 56. If the kit price or fixed cost changes, update the prompt and checking calculations; this table will no longer apply.

Availability depends on your account

The announcement describes a rollout in Chat: October 7 for Plus, Pro, Business, and Enterprise; October 8 for Free and Go, with Enterprise subject to admin settings. This release does not change models in Work or Codex. We have not checked a particular account and cannot promise identical controls or access for everyone.

Start with the fictional headcounts 6 and 18, and calculate both totals yourself. If you do not get controls, complete the same task with the table. The useful outcome is knowing your kit count and checking the calculation, rather than trusting a displayed total.

Primary source: OpenAI’s October 7, 2026 announcement

Source checked October 14, 2026. Availability and feature behavior may change.