Gumball Rule
Number rules · 30 levels
Crack the machine's secret rule, then pass its exam.
How to play
- The machine only takes numbers that fit its secret rule. The trays show some it took ✓ and spat out ✗.
- Type a number and press Test to see what it does. Tests are limited 🪙.
- Press 📝 Exam and mark each number ✓ takes or ✗ spits. All 5 right wins!
The examples always fit an obvious rule and a sneakier one. Test a number where the two would disagree. Rules use even/odd, size, digits, digit sums, times tables, squares and primes. A wrong exam shows your mistakes, gives a test back and a fresh exam.
Teeter, Tint and Echo Heist are free starters. Other games unlock through earned game choices or permanent packs. Your progress stays in the browser; optional sign-in saves it to your website account.