Who doesn't know this from their daily teaching practice? As soon as your students are allowed to use calculators, mental arithmetic skills become a thing of the past. For the simplest calculations, they quickly reach for the calculator. However, calculating in your head is not only essential in school but also in everyday life and professional settings. With the exercises in the following volume covering all important curriculum topics for grades 5 and 6, your students will become proficient in working with numbers again: Each page features two sets of exercises that you can use as handouts, OHP transparencies, or with minimal effort as flashcards. Detailed solutions on the back of each sheet allow for joint or individual checking. Numerous tips and tricks for effective mental arithmetic complete the offering. The topics include: - Natural numbers - Basic arithmetic operations.