Miquon Math is a series of 6 math workbooks designed to be used in 1st through 3rd grade. They are named by color and not by grade level, so that an older child can use them without feeling they are "remedial". The workbooks are designed to be used with Cuisenaire Rods. I have had the books for a couple of years but have only started using them this year as a supplement for my 3rd and 4th graders. I hesitated using them before because they have an unusual format -- the pages don't necessarily have to be done in order, and are grouped by topic rather than in sequential chapters. Multiplication is introduced along with addition in first grade, and advanced concepts such as squared numbers and pre-algebra are introduced through use of concrete manipulatives. However, my 3rd grader now says she "loves this kind of math" and both the children have shown a better grasp of what numbers mean since they have started using the books. We've discovered that when the manipulatives come out and are used to illustrate concepts, the "littlies" want to join in. My 5yo was watching carefully as my 8yo tried to figure out the square of 4, and suddenly announced "It's 16!" He was so proud of himself!
I have ordered the Orange Book (the first one in the series) to start with my almost 6 year old. After completing the Miquon Series, a child can go straight into Saxon Math 54 or 65.