mahblife

Live · on the home server since Oct 19, 2026 · Education

Math League

A Kumon-style math game for my son and daughter. An entry exam places each of them, every session insists on mastery before moving on, and they write the answers by hand on the iPad.

The game on an iPad with a demo player: a two-digit addition on a paper-style card with a scratch mark, the answer 64 handwritten in the box on the right, a hockey rink and scoreboard above
figure 01: a two-digit problem answered by hand. The card is scratch paper, the box on the right is read by the recognizer · demo player
summary

01 / problem

My son is in third grade, had finished sums to 100 and two-digit subtraction with regrouping, and struggles to focus. Kumon-style tutoring was the right model, but the centre cost too much and its schedule kept colliding with ours. I wanted the same discipline at home: short, daily, between meals, anywhere there is an iPad. His sister, in kindergarten, needed the same thing at her level.

02 / approach

One engine, two worlds. An adaptive entry exam places a kid on a 57-skill path; mastery means two passing sessions in a row; timed drills follow the facts the state standards say must be from memory. Answers are handwritten and read on the device. The leveling rules are keyed to grade, never to theme, so the kindergarten rules are not a hockey special case. Three Stitch reviews later, I kept the plain screens and took eight small ideas.

03 / result

Running in Docker on my home server since Oct 19, behind a sign-in, installable as a home-screen app on the iPad and the iPhone. Both kids have played it, two days each so far; no other families yet while I shake out bugs. The digit recognizer scores 99.2% on the MNIST test set and read 0 of 31 answers wrong in a scripted game. 32 engine and API tests pass, and a layout check at 7 screen sizes reports 0 problems in both worlds.

architecture

iPad → home server → engine

iPad or iPhonehome-screen web app, no build step; handwriting read on the device by a 3-layer CNN with int8 weights (76 KB, ~2 ms a digit); unsent answers queue in the browser until Wi-Fi is back
Home serverPython standard-library HTTP server and SQLite in a read-only container; player and coach accounts, weekly standings, audit log; reachable from outside only behind a sign-in
Engine57-skill path (K through grade 3), binary-search entry exam plus one timed drill per stage, Leitner fact cards, mastery and step-back rules per grade, rematches for misses
Worldshockey arena and unicorn meadow: every kid-facing word, picture and sound swaps; nothing in the engine does
timeline, newest first
  1. Oct 26 Both kids have played: two days each
  2. Oct 22 Speed rungs on the must-be-fluent facts; handwritten answers with scratch work on the card; 32 of 32 tests pass
  3. Oct 21 Kindergarten ladder grows from 3 rungs to 9; rules keyed to grade; third Stitch review across every screen; iPhone fit checked at 7 sizes
  4. Oct 20 Unicorn Meadow, a second world on the same engine; fingers and touch-counting for the youngest; phone layouts
  5. Oct 19 Engine, server and front end built and deployed to the home server; first Stitch comparison; animations and the arena skin the same day
gallery · demo players, no family data
Unicorn Meadow at kindergarten level: 2 minus 1 shown as a hand with one finger folding down and the words two and one under the numbers, a Hear it button, a pastel number pad with a Fairy help key
kindergarten, unicorn world: take-away as fingers folding, number words under the digits, a fairy instead of a coach
Coach's replay sheet after a miss: 2 plus 8 is 10, the wrong answer 9 crossed out, the two numbers as pucks, one worked step and a Ready for the rebound button
after a miss: the coach's replay shows one step, then a rebound shot for half the points
Coach's office with two demo players, one card each: grade, world, current skill, skills mastered, games this week, 7-day accuracy, streak, coins, and an Adaptive switch
the coach's office: one card per kid, and a switch to turn adaptive leveling off and set a skill by hand
Side by side: the first version of the game, a plain card with a number pad, next to Stitch's redesign with a nav bar, countdown clock, streak banners and stat labels
the redesign I turned down: Stitch's take (right) is busier than a kid who can't focus can use; eight small ideas from it were kept
what i'd do differently
Too early to say: it has been played on two days per kid. What I'm watching for is whether a 30-problem game is too long for my son, whether the 5-second fact clock feels like a game or a threat, whether the recognizer misses his 4s and 7s, and whether the stretch problems land as a treat or a scare for my daughter. The other families' leaderboard waits until those answers are in.