Rechentrainer Kopfrechnen is an Android application developed by Volker Dudda that falls under the category of Education & Reference. It is a free app that offers a comprehensive platform for practicing mental arithmetic. The app is designed to help users master the basics of arithmetic and improve their math skills by practicing for just five to ten minutes a day.

Rechentrainer Kopfrechnen offers a wide range of exercises that cater to different levels of difficulty. Users can set the range of numbers from 20 to 999,999, choose between addition, subtraction, multiplication, and division, and even practice squaring, cubing, and other powers. The app also offers individual practice for mathematical series and the option to include negative numbers in the exercises.

The app provides a simple evaluation at the end of each exercise series. Rechentrainer Kopfrechnen is an excellent app for anyone looking to improve their mental arithmetic skills.