We used it. Overall it was a good program. We had the Physics one that was geared for grades 4-6th. My dd did this in 4th grade. We got the whole thing-- text, student workbook, and teacher book. The text was simple to read/understand, there was an experiment/lab for each chapter. The teacher's guide explained things further, gave answers to the review questions, and (most importantly to me) it gave me a clue as to what to expect for the lab. There were ten units. We did just one unit/month and did other science the rest of the month (random experiments, etc). A motivated kid could do the program on his/her own.
I can't remember whether it is a secular program or not. I couldn't find anything remotely religious in the physics curriculum. I imagine that the Biology one would be more of a place for creation/evolution topics.
We did think that they should have listed the age group as grades 2-6 instead of 4-6 because many younger kids would have been fine with it. You could do one unit/week if desired. If you have a particularly advanced child, you may consider going up a level. This isn't written for a "gifted" audience. We did really like it; only downside for us is that my dd doesn't like being required to read the chapter first. She also wanted things to explode and physics wasn't the place for that.
Amy
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