Math at the Speed of Escape
The lava is rising. The asteroid is closing in. Your only weapon? Mental math.
Download on the App StoreFree · iOS
The lava is rising. The asteroid is closing in. Your only weapon? Mental math.
Download on the App StoreFree · iOS
Number Run turns mental math into a survival game. Answer arithmetic questions correctly to sprint ahead — hesitate, and the danger catches up. Fast enough to be thrilling, simple enough for everyone.
Each world has its own atmosphere, music and chaser. New worlds are on the way.
A blazing wall of lava chases you through a scorched landscape. Answer fast or get burned.
A massive space rock is hurtling toward you across a dark alien terrain. No time to think.
The horde is relentless. Navigate a post-apocalyptic night and keep running.
A wall of water is surging behind you. Can your mental math keep pace with the ocean?
A spinning vortex tears through everything in its path. Run. Calculate. Survive.
A digital plague spreads through the grid. Only your logic can contain it.
The fabric of space is collapsing behind you. The laws of physics won't save you — math will.
Number Run is dead simple to learn — and surprisingly hard to master.
A math question appears on screen. Addition, subtraction — all designed to be fast mental math.
Pick from 3 choices. Tap the right one and your runner sprints ahead. Wrong? The chaser gains ground.
Answer all 25 questions before the danger reaches you. Complete the level to unlock the next.
Clear every level in a world to unlock the next. How far can your mental math take you?
Free to download. No ads. Just math and speed.
Download on the App StoreAvailable on iPhone and iPad · iOS 16+
Short version: we collect nothing.
Number Run is an indie iOS game developed by Calvin Skyrunner. You can reach us at contact@calvin.be.
None. Number Run does not collect, store, transmit, or share any personal data — ever. The game runs entirely on your device.
The only data the app saves is your game progress (levels completed, worlds unlocked) and your tutorial preference. This data is stored locally on your iPhone or iPad using Apple's standard storage and never leaves your device.
Number Run does not use any analytics SDKs, advertising networks, crash reporting tools, or third-party services of any kind. No data is ever sent anywhere.
Number Run is designed to be fun and safe for all ages, including children. Because we collect no data whatsoever, the app is fully compliant with children's privacy regulations (COPPA, GDPR-K, and similar laws).
The app is distributed through the Apple App Store. Apple may collect certain analytics and crash data as part of their standard platform services, subject to their own Privacy Policy.
If we ever update this policy, the new version will be posted at numberrun.calvin.be with an updated date below.
Questions? contact@calvin.be
Last updated: February 2026