Goal: use all four cards and + − × ÷ to make exactly the target shown above the cards: 24, 36 or 48 (choose a fixed target or Surprise me in the menu).

1. Click a card, then an operation, then another card.
2. The two cards combine into one new card.
3. Keep going until one card is left. If it matches the target, you win!

Cards are always whole numbers, so ÷ only works when it divides exactly, and − can't go below zero. Every puzzle can be solved. Some need brackets: combining two cards first works like brackets, so 8 − 2 and then × 4 is (8 − 2) × 4.

Keyboard: 1–4 pick a card · + − * / pick an operation · Backspace undo · R reset · S reveal · F2 or N new puzzle

Copper Kettle is a cozy static adaptation of Make 24 by Joshua Muller (JML), 2026. The complete solo arithmetic engine, solver, puzzle generator, timers, undo, expression formatting, reveals and keyboard controls are retained.

New interface, target selector, accessible cards and original GPT-generated tea-table artwork integrated into the playable area. Classroom race/server mode is omitted. Free, no backend or account.

MIT license · Source and modification notes. All preferred-form application source is bundled locally. Tags: github-source, game.