What does an athlete need to win a competition? Train, and train again! What does a student need to do to understand what a percentage is? Train too! This workbook offers an exciting and unusual training program. It involves solving interesting and non-standard problems. A variety of tasks will make training fun and easy, and will certainly contribute to the understanding of the concept of percentage, will help to work correctly with percentages not only at school, but also, most importantly, in everyday life.