Martial arts

The ladder

1. Ages 3–5
   • Which Belt Comes Next?Put the belts in order and find the nextOpen →
2. Ages 6–8
   • Every Way to Make 15Find every way to reach fifteen pointsOpen →
   • Count the MovesCount a form's moves and double for both sidesOpen →
3. Ages 9–14
   • A Number Line With No ZeroCount promotions across ranks with no zeroOpen →
   • Reading a BracketCount the matches a bracket needs and add the byesOpen →
4. Ages 15–18
   • The Physics of a Board BreakWork out impulse and energy for a board breakOpen →

Two rules every rung keeps

The Fade Rule. Every game ends on a plain screen: the same numbers with the martial arts words gone, so the maths leaves with you.

The Own-Lane Rule. Your numbers are compared only with your own past, never with anyone else's, and they stay on this device.

Problems built on something you love help most when the context carries the maths, not when it decorates it. These ladders are a design, not a promise.

Ask a grown-up tonight: “What did you notice about how the bracket was drawn up?”