The 100-Square Drill, Reimagined for Little Hands
百ます計算 — hyakumasu keisan — meets gentle, adaptive play
An operation in the corner, numbers across the top and down the side — your child fills every cell. Math Grid digitises the time-honoured Japanese 100-square calculation drill with adaptive difficulty, real-time battles and family leaderboards. For ages 5–7 and up.
One Grid, Endless Practice
From a gentle 3×3 start to the legendary 100-square — Math Grid grows with your child.
Four Operations, Four Grid Sizes
Addition, subtraction, multiplication and division across 3×3, 4×4, 5×5 and the full 10×10 — the classic 100-square.
Auto Adaptive Difficulty
Levels up after two strong rounds and gently adjusts down when needed — never framed as failure, always the right challenge.
Battle a Friend
Race a friend in real time — challenge an online friend with a tap, or share a 6-digit room code. Both play the identical grid, fastest time wins. Only a first name and avatar are shared to run the match.
Friends & Presence
Add a friend with a simple code, see who's online with a live dot, and compare weekly and all-time stars. Friendships form only when both sides accept.
Profiles & Family Leaderboard
Every player gets their own avatar and colour. The family leaderboard celebrates star champions and the fastest fingers in the house.
Star Season
Rotating bonus-star events award double or triple stars on a featured operation or grid size — a fun reason to practise every kind of grid, not just the easy ones.
Heatmap & Smart Practice
A GitHub-style heatmap shows practice day by day, while facts a child keeps missing quietly reappear until they're mastered.
Joyful by Design
Stars, streaks, confetti, gentle sounds and haptics make every round feel like a celebration, not a test.
How the 100-Square Works
The drill that generations of Japanese schoolchildren grew up with — three steps to math fluency.
Pick an Operation & Grid
Choose + − × or ÷ and a grid size — or let 🪄 Auto pick the perfect level automatically.
Fill Every Cell
Numbers run across the top and down the side. Your child combines them with the corner operation and fills the whole grid.
Beat the Clock, Level Up
Earn stars, build streaks and watch the heatmap fill in. Two strong rounds and the difficulty steps up on its own.
Truly Private. Made for Families.
Built with care for young learners — and built to keep your family's data private.
Parental Gates Everywhere
An adult challenge protects the parent dashboard, all purchases, external links and sharing — kids stay safely inside the game.
A Real Parent Dashboard
Set per-operation levels, review accuracy charts, see the list of tricky facts your child is working on, and browse the session log.
Speaks Your Language
English UI localised into Japanese, Chinese (Simplified), Korean, Spanish, Portuguese (BR), French and German.
Encouragement, Not Pressure
Auto difficulty adjusts down gently and never frames it as failure. Stars and streaks reward showing up, not just speed.
Start Free, Grow with Them
The full four-operation drill is free. Upgrade when your child is ready for the 100-square.
Free
- 3×3 & 4×4 grids
- All four operations
- 🪄 Auto adaptive mode
- Battles with friends
- Up to 3 profiles
Premium Annual
- Everything in Free
- All grid sizes
- The full 100-square (10×10)
- Manual level picking
- Premium avatars
- Progress backup & restore
Family
- Everything in Premium
- Up to 6 player profiles
- Family Sharing
Also available: Monthly Premium at $2.99/month. All plans include a 1-week free trial.
One Grid a Day Keeps Math Fear Away
Math Grid is now on the App Store — private by design, with no ads and no tracking.
Download on the App Store