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Ratio & Proportion
7 apps to play — grouped by age.
🎒 Ages 9–14 · Grades 4–8
TradeForge
Ages 9–13 · Gr 4–8 Level 3
A day on the job with twelve trades, for ages 9–14. The electrician sizing a circuit, the plumber’s slope, the baker’s ratio, the nurse’s dose — each worker is one piece of real math. You see a real job, GUESS the answer, then watch the worker compute it and explain. Applied arithmetic + a look at real careers. On-device, no accounts.
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RatioRealm
Ages 11–12 · Gr 6–7 Level 2
Scale ratios on a double number line, work recipe/map/blueprint scale problems, judge which mix is stronger, and practice ratio, rate, proportion & percent across 16 kits.
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SpokeForge
Ages 10–13 · Gr 5–8 Level 3
How does a bicycle turn one push of your legs into a wheel spinning four times over? Gears. The front teeth divided by the rear teeth is the gear ratio — how many wheel turns you get per pedal — and it sets everything: how hard the pedals are, how far one push carries you, how fast you go. Predict the ratio, then build your own gear in the workshop. Real, tiny, deterministic maths — no internet. Ages 9–14.
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BridgeForge
Ages 10–12 · Gr 5–7 Level 3
Build bridges between math and everything else. Match a math idea — ratio, symmetry, rate, probability — to the real-world moment in art, music, science, sport or code that actually uses it. Plus cross-curricular Concepts checks. Ages 9–14.
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SplitForge
Ages 10–13 · Gr 5–8 Level 3
Enter your OWN swim/run/bike times and learn the middle-school ratio & percent core through them — pace as a unit rate, percent improvement, negative vs positive splits, yards↔metres, and qualifying cuts as inequalities. Five little coaches, each one math move. On-device, no names, no upload, no AI.
Play SplitForge →
🎓 Ages 15–18 · Grades 9–12
CentralForge
Ages 15–18 · Gr 9–12 Level 4
You are the central bank. Set one lever — the policy rate — and steer inflation and jobs, but everything you do arrives with a lag. Hike to cool prices and inflation barely moves for a year; hold too long and you over-tighten into a recession; face a supply shock and there is no clean move at all. Predict the economy, then run it yourself. All exact, all on your device. Ages 15–18.
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NimForge
Ages 15–18 · Gr 9–12 Level 5
The mathematics of who wins, for ages 15–18: play Nim (and its last-token-loses twist), then let the engine reveal WHY a position is won or lost — the Nim-sum, Sprague–Grundy values, and the golden ratio hiding inside Wythoff’s game. Play, conjecture, and the engine checks every small position. On-device; nothing leaves your device.
Play NimForge →