The workbook "I Can Calculate 1" is now also available in A4 size with nearly identical content. Like the smaller A5 student workbook, it is tailored to the individual learning and performance level of the child. It was designed by teachers for independent work. The student works at their own pace and ability level, self-directed in their own workbook. It includes a writing number course, addition and subtraction within the number range up to 10, and an introduction to the number range up to 20. "I Can Calculate 2" covers addition and subtraction up to 20. Additionally, it introduces the number range up to 100 and includes a final overview of the learning objectives covered. The number range up to 100 can be independently worked on by students in the workbook "I Can Calculate 3.".