Form10

Form10 is a small mental-arithmetic puzzle for iPhone — the famous "train game", rebuilt.

You see four digits. Combine them so the answer is exactly 10. Use plus, minus, times, divide. Use brackets if you need them. Use every digit, each one once.

That's the whole game.

THREE WAYS TO PLAY

Daily — One puzzle a day, 20 seconds to solve it. Solve it on consecutive days to build a streak.

Endless — Solve as many as you can in one run. The puzzles get harder and the timer tightens as you go. Save your spot at any level boundary; pick up later.

Practice — No timer. Pick a difficulty and play at your own pace. Stuck? Tap to reveal a solution.

SIMPLE BY DESIGN

No accounts. No sign-up. Free to download — no ads, no in-app purchases. Your scores stay on your phone. Apple's Privacy Nutrition Label says "Data Not Collected" because none is.

Made on a train. Mostly.