Privacy Friendly Reckoning Skills helps you improving your mental calculation skills in the four basic calculating operations. For each game, the player can choose between the four basic arithmetic operations and four difficulties (exercises up to 10, 100, 1000 and 10000).
After finishing an exercise round the player receives a score which depends on the number of exercises answered correctly and the time it took to answer all ten exercises.
After every game there is an overview which shows whether the exercises were solved correctly. It is also possible to choose "Direct Feedback" in the settings. If direct feedback is chosen, the player will receive feedback whether the exercise was solved correctly after each single exercise. This App requires minimal permissions and is part of the Privacy Friendly Apps group developed by the research group SECUSO at Technische Universität Darmstadt.