This is a screenshot guide to Kalkulko, an arithmetic practice app from Yellow Bench. The examples include earlier English screens and Czech simulator screenshots, explained here in English.

This setup example selects ten questions, numbers up to twenty, and addition and subtraction. You can choose a different question count, range, or operation group for another round.

Ordinary rounds are timed. This English game screen shows the timer, question counter and keypad. The saved example coming next contains one incorrect answer.

Completed games can be reviewed in game history. The app stores the last fifty completed games on this device, including recorded answers and correct solutions.

Here is a Czech example from September eighth. Seventeen plus two was answered as twenty. The detail preserves that answer and shows nineteen as the correct result. The mistakes filter is enabled.

The highlighted action means: practise mistakes from this game. It starts a separate round without a timer or leaderboard. Each saved mistake appears once. The original answers remain in the original record.

This saved practice result shows one correct answer out of one. It has no elapsed time or leaderboard score. The active practice screen is not shown in this guide.

Kalkulko is free and ad-free. The official Android and iPhone download links are in the description. Choose a short round, then use the saved answers for review.