Each machine has a goal, such as “Make 18”. Change the machine — swap the order of the number gears, or switch which track the number rolls down — then press Run. The number travels gear by gear, and the machine wakes up when the result matches the goal.

Before running, your child can guess what number will come out. A correct guess earns a star. Guessing is optional; they can always just run the machine.

Tap Hint under the machine for a nudge from Zolo. After a run that doesn't reach the goal, the machine shows where the number went, so trying again is part of the game. Undo takes back the last change.

A mystery box hides a rule. Test a few input numbers and look at what comes out; once there is enough evidence, choose the rule you think it is.

Each world has 19 machines on its adventure map: seven story machines and twelve practice machines with numbers up to 20, 100 and 1000. The next machine is highlighted on the map, and solving machines earns a sticker for each one in the Sticker Book.

Puzolo follows the iPhone and iPad silent switch. Turn silent mode off, turn up the volume, and check that sound is on in the Grown-ups tab.

Yes. Puzolo follows Settings › Accessibility › Motion › Reduce Motion.

Open the Grown-ups tab and choose Reset all progress. A short grown-up check (typing a number written in words) keeps young players from doing this by accident. Solved machines, stickers, stars and first-visit tips start over.

Progress is stored only on the device. It comes along when you restore a device backup (for example iCloud Backup) that includes app data; otherwise a new device starts fresh. We can't restore progress, because we never receive a copy.

No. Puzolo has no ads, no accounts and no in-app purchases, and it works fully offline. See the privacy policy.

iPhone and iPad with iOS 17 or later. The game is in English.