Math Made Easy workbooks by DK Publishing
Math Made Easy is a series of inexpensive math workbooks for elementary grades. The books are 200 pages long, providing practice for all the major topics on each grade.List price: $14.99 per book.
Review of Math Made Easy books
I really liked these workbooks. There is no teacher's guide and very little instruction. But as a guide as to what skills my son should master, it has been very good. Since I am used to pulling together my own lessons and I have had lots of college level math, this was not a problem. Naturally I used other tools as well (especially flash cards). But I have found that using these workbooks as our core, he has consistantly scored well above grade level on his standardized tests.