Information about the title: Differentiation: All tasks are divided into three levels of differentiation, which are immediately recognizable. Review tasks: These serve to reinforce the material and prepare for new learning content. Self-assessment: Solution numbers, solution words, and number images encourage self-assessment. Word problems: The handling of word problems is built up step by step. Technical language: It is systematically and consistently introduced through understanding and using technical terms. Project ideas: Math Friends offers interdisciplinary project ideas for every grade level. Information about the series publication: The concept of Math Friends ensures the successful development of fundamental mathematical competencies in all children. The teaching material consistently employs means of differentiation, independent work with the help of self-assessment, and reinforcement.