Support
Numfold for iPhone, iPad and Apple Watch
Email [email protected]. Replies within two business days. Say which device you are on, which game and mode, and what you expected to happen. Nothing in the app can send us your progress, so a screenshot is the best way to show us a puzzle.
How to play
Every game asks for one digit at a time on a keypad. A right tap folds into place at once. A wrong tap shows the right digit for a moment, then moves on, and costs one of the day's ten hearts (see Hearts below; Zen mode has no hearts). After the round, the steps you missed are listed so you can look at them again.
Digit Chain
- Start with the first digit. Add the next digit to it.
- If the sum goes past 9, add its digits: 12 becomes 1 + 2 = 3.
- Tap the result each time. The last tap folds the whole number to one digit.
The keypad runs from 1 to 9. Levels grow from 3 digits to 16. The fold rule switch at the top of the game's hub (also in Settings › Digit Chain fold rule) offers three rules: Root (add the digits: 14 becomes 5), Last digit (keep the last digit: 14 becomes 4) and Gap (the difference between the two digits, smaller from bigger: 7 and 3 make 4). Last digit and Gap add a 0 key.
Carry
- Add the columns from the right, one at a time.
- Tap the digit that goes in the column. If the column adds to 14, tap 4.
- Keep the carry in your head and add it to the next column.
Some levels are take-away, where you borrow instead of carry, and some add three numbers. Numbers grow to six digits. If holding the carry is the hard part, Settings › Carry: show the carry dot marks it for you.
Ladder
- A start number appears, then one operation at a time.
- Work each rung out in your head. The rungs disappear as you go.
- At the top, pick where you landed from four answers.
Levels grow from 3 rungs to 14. Every division is exact and the total stays between 0 and 99. Settings › Ladder pace is Slow, Normal, Fast, or Tap to advance, where each rung waits for your tap.
Balance
- One digit is missing from the equation.
- Tap the digit that makes both sides equal.
- The scale levels when you are right.
The twelve levels go Add, Take away, Times, Three numbers, Brackets, Times and add, Mix, Big add, Big take away, Times to twelve, Big mix and a 12-question Marathon. The other levels have eight questions each. The missing digit is always a single digit, even when the numbers around it have two.
Tens
- One cell in the grid lights up.
- Tap another cell so the two digits make ten: 7 wants a 3.
- Both cells clear. Empty the grid.
Grids are 4 by 4 on levels 1 to 4, 5 by 4 on levels 5 to 8 and 6 by 4 from level 9. The digits run from 1 to 9 and every cell has a partner somewhere in the grid; when several cells carry the right digit, any of them counts. On the watch, the grid is always 4 by 4.
Times
- Multiply the top number by the small one, one column at a time from the right.
- Tap the digit that goes in the column: 7 × 6 = 42, tap 2.
- Carry the tens into the next column, like Carry.
The keypad runs from 0 to 9. The top number grows from two digits on level 1 to eight digits on level 12. Odd levels multiply by 2 to 5, even levels by 2 to 9. The carry dot setting applies here too.
Modes
| Practice | Twelve levels per game, three stars each, no clock to beat (three stars are for a clean round under par). Clear a level to unlock the next. Your best time per level is kept. Back one forgets your last answer and shows that step again; a heart already spent stays spent. |
|---|---|
| Sprint | Sixty seconds, as many steps as you can. The last five seconds tick. Your best score can go on the Game Center Sprint leaderboard for that game. |
| Endless | Puzzle after puzzle, starting at level 1. Two clean puzzles in a row and the level goes up; two or more misses in one puzzle and it goes down. Runs on your daily hearts; when the last heart goes, the run ends. |
| Today's six | One puzzle per game each day, the same for everyone. All six done is a perfect day. At least one a day keeps the streak. Your time on each daily goes on that game's daily and weekly Game Center leaderboards when you are signed in to Game Center. |
| Zen | Any game, puzzle after puzzle at your highest unlocked level, no hearts, no clock. Part of Numfold Complete. |
Hearts and Numfold Complete
You start every day with ten hearts. A wrong answer costs one, in every mode except Zen. When the last heart goes, the round stops and the app shows two ways on:
- Wait. The hearts come back at midnight on your device; the sheet tells you how long that is.
- Numfold Complete. One purchase, no subscription: unlimited hearts and Zen mode. Family Sharing is supported, so one purchase covers everyone in your family group. The price is shown in the app in your local currency.
Numfold Complete is a one-time App Store purchase tied to your Apple Account. After reinstalling, or on a new device, tap Settings › Restore purchases (or Restore purchases on the Complete sheet) and it comes back at no charge.
Your numbers
The bar-chart button on the Home screen opens Your numbers: accuracy and average seconds per step for each game, a heat map of the Digit Chain digit pairs (darker is slower, with your slowest pair called out), and a bar per day for the last 14 days of accuracy. It fills up as you play. Nothing on this page leaves your device.
Why it works
The book button in each game's hub opens short cards on the maths behind the games: why folding always ends at one digit (the digital root), casting out nines, what the carry really is, pairs that make ten, holding a number in your head, and why an equation is a balance. The question-mark button next to it shows the three-line how-to-play card again.
Widgets, Siri, links and sharing
- Widgets. Add the Numfold widget to your Home Screen or Lock Screen to see which of today's puzzles are done and your streak. Tap a game to open its daily puzzle. It refreshes every hour and at midnight.
- Apple Watch complication. Shows your streak and how many of today's six are done; circular, corner, inline and rectangular styles.
- Siri and Shortcuts. Say “Play today's puzzle in Numfold” or “Play today's fold in Numfold” to open the daily, or “Practice in Numfold” to open a game. Both actions take a game as a parameter in the Shortcuts app.
- Challenge a friend. After a Practice or daily round, Challenge a friend shares a link that opens the exact puzzle you played, with your time. The link starts with numfold:// and needs Numfold installed to open.
- Share today's card. After a daily, Share today's card makes a picture of your result, tile by tile, with the streak and the day, without giving the answer away.
- Hardware keyboard. On iPad, or on a Mac, the digit keys answer the keypad.
Settings
Open Settings from the gear on the Home screen.
- Numfold Complete and Restore purchases, described above.
- Sounds, Haptics and Big keys for a larger keypad.
- Teacher mode: no clocks anywhere, and big keys. For classrooms and anyone who would rather not be timed.
- Look: the dark look, the light look, or whatever your device is set to.
- Digit Chain fold rule, Carry: show the carry dot and Ladder pace, described above.
- Sync with iCloud: carries stars, best times, points, hearts, stats and the daily streak to your iPad and Apple Watch through your own iCloud account. It is on unless you switch it off.
- Reset all progress: clears stars, best times and the daily streak. It asks first.
Frequently asked
Why “Numfold”?
Because every game folds a number down. A long number folds to one digit, columns fold into a sum or a product, a ladder of operations folds into where you landed, a scale folds level, and a grid folds away in pairs of ten. Num, fold.
Is it free?
Free to download and free to play: every game, every level and every mode, with ten hearts a day and no account. When the hearts run out you can wait for midnight, or buy Numfold Complete once. There is no subscription.
I bought Numfold Complete and it is not showing
Tap Settings › Restore purchases while signed in to the Apple Account that made the purchase (or to a member of the same Family Sharing group). If the App Store shows the purchase but the app does not, email us with the receipt date.
How does Today's six work?
Each day the app builds one puzzle per game from the date, so everyone gets the same six. The day changes at midnight on your device. Finish all six for a perfect-day star. Play at least one and your daily streak grows by one; the streak shows until the end of the day after your last daily, so you always have a full day to keep it going.
Where are the leaderboards?
In each game's hub, under the daily card, once you are signed in to Game Center (iOS Settings › Game Center). Daily and weekly boards rank the time on that game's daily puzzle, lower is better; the Sprint board ranks your score. Leaderboards are optional: without Game Center everything else works the same.
Sounds don't play
Check that Settings › Sounds is on, then turn the volume up with the side buttons while the app is open. Numfold's effects play even with the Ring/Silent switch on silent and they mix with music you already have playing. If you use AirPods or another Bluetooth device, the sound goes there. Haptics are a separate switch, Settings › Haptics.
My progress isn't on my iPad or watch
Make sure Settings › Sync with iCloud is on on each device, and that they are signed in to the same iCloud account. Sync goes through Apple's iCloud and usually takes a moment; open the app on the other device once to let it pick up the change. When two devices have both played, their stars, best times, points and streak are merged, so nothing is lost. Hearts merge too: the lower count wins on the same day, because hearts spent anywhere are spent.
Reset my progress
Settings › Reset all progress, then confirm. This clears stars, best times and the daily streak on that device. If Sync with iCloud is on, the reset syncs too, so your other devices follow. Numfold Complete is a purchase, not progress; it stays.
Which devices does it run on?
iPhone and iPad with iOS 26 or later, and Apple Watch with watchOS 26 or later. The watch app runs on its own; it does not need the iPhone nearby, plays all six games, and shows no ads.
Is it suitable for all ages?
Yes. It is rated 4+, with no accounts, no chat, no ads and no tracking. Level one of every game uses small numbers, and Teacher mode turns off every clock.
Privacy
No account, no analytics, no third-party code, nothing of ours on a server. The privacy policy says exactly what that means.