A fundamental understanding of numbers is an essential prerequisite for mathematics instruction in secondary education. The student workbook "einfachmathemagisch - Numbers and Types of Numbers" trains and consolidates basic mathematical knowledge. Calculating with numbers requires first engaging with the nature of numbers. Therefore, this volume deals with numbers and types of numbers. This workbook focuses on the development and internalization of number understanding. Furthermore, students should gain an idea of the different magnitudes of numbers. Various representations of numbers are discussed. Additionally, rounding numbers is addressed. Rules of divisibility for numbers are mentioned. Students receive an overview of different types of numbers. They will solve number puzzles as well as logical number sequences.