Marked by difficulty level, students can expect a variety of tasks on the topic of percentage calculation. Intermediate tests at the end of the chapters allow for the review of what has been learned. The solutions in the removable answer section are presented in detail and are easy to understand. This enables even weaker students to learn successfully. At the end of the booklet, there are several exercises specifically for the qualifying secondary school diploma. Some puzzle tasks add variety to the strict practice and contribute to increased motivation.