Whoa this thread is confusing.
There are two similar named science programs-
Real Science for Kids which has 3 levels of ten week programs, Bio, Chem, Phy
Then there is R.E.A.L. Science from Pandia Press. It has two year long programs available level 1 Life and Level 1 Earth and Space. Level 1 Chem is almost available and there are plans to make higher levels of them as well as levels of Physics. They are only one year each, but you could use level one for any of 1-4th grade.
Yes they say that Level 1 Life is suitable for 1-4 graders. Quite frankly I think that is just wishful thinking. We loved Life and Earth and Space, and really wished Chem had been ready at the beginning of this year. But I agree that they don't spread nearly the ages that they "planned" them for.
Assuming you do one year on bio, earth, chem, and phy, then they would recomend Level one for 1-4. Eventually they hope to have a level 2 that would be for grades 5-8 (and I think even a level 3 for high school, but don't hold your breath