Saving up

The ladder

1. Ages 3–5
   • Save Up for ItCount on until there are enough coins for the toyOpen →
2. Ages 6–8
   • Weeks to the GoalCount the weeks of saving to reach a goalOpen →
3. Ages 9–14
   • Compound GrowthPredict how saved money grows, then watch it compoundOpen →
   • The Rule of 72Compare simple and compound growth and estimate doubling timeOpen →
4. Ages 15–18
   • The Fee That GrowsWork out what a small yearly fee costs over twenty yearsOpen →
   • Time MultipliesPredict how savings grow, then compare the numbersOpen →
   • Pay It DownSlide a monthly payment and watch the debt changeOpen →
   • Eggs in BasketsAverage many independent things and see how much they wobbleOpen →

Two rules every rung keeps

The Fade Rule. Every game ends on a plain screen: the same numbers with the saving up 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 would you save up for, and how many weeks do you think it would take?”