Key To math series are the only math books we ever buy. They are simple, student-led and environmental friendly! You read it right, they are environmental friendly. The workbooks contain about 45 pages and are printed on thin paper similar to newsprint paper.
They are also simply laid out with easy to understand directions, so minimal instruction is needed. If you do need to help your child, the examples provided in the books are the perfect teaching tool. Simply write the example on a chalkboard or piece of paper and walk your child through the example.
The series also comes with an answer key, which I highly recommend. The curriculum is sold individually or as a set, and I think they are really well priced.