When my oldest daughter completed all six books in the Miquon Math series, I was faced with the question, "What comes next?" After many trials and errors, and two kids later, I finally hit upon Singapore Math. I really like the way concepts are taught in this program. It is very clear and straightforward and in many cases it teaches more than one method for performing the task at hand. While it does not cover some concepts (negative numbers, for example) it does a thorough job teaching the concepts it does cover. I particularly like the fact that the word problems actually require thought and are not just a matter of plug-and-chug with the materials learned in the most recent lesson. Another factor that I like is the amount of geometry included. I feel that this program gives children a solid basis on which to build higher-level mathematical knowledge in their later years. For more information on this curriculum, visit the Singapore Math website. There you will find product descriptions, placement tests, and a forum where you can talk with other users, ask questions, etc. If you have completed the Miquon materials, level 4A is a good starting point.