My rising 3rd and 5th graders are my primary concern about this. We switched to Singapore Dimensions last year. The textbook has many problems as do the workbooks. From experience, I know the workbooks offer different types of problems. So I do think it is necessary to have the entire kits. The issue is that the lessons really are not CM-appropriate when it comes to time spent on the lessons themselves. I am not even sure other math curriculums would work, given time constraints. I do not want to hop around in math, and since the SCM math series stops at book 4 right now, I think we should probably use Singapore again. How do you make the lessons appropriate in length? We took two days for many lessons this last year with my 4th grader, and they were still long for us. If there was another CM math, I’d consider it. Do any exist? We did try Master Books. Whatelse could you do without taking two years to do one level?