Understanding God’s World is a 4GRD Abeka text. It’s about 200 pages long and full color. you can see the full contents at the Abeka site. There are a few experiments the first few weeks and then those stop until about Week 15. For my fourth graders, both time, I’ve had to read this aloud for at least hal the year, but they really enjoyed it.
Also, this book has the 25 state birds (many states chose the same one, so there’s not 50) sprinkled throughout the text. So, every week or so, the child completes a page in a “bird” notebook.
Apart from smart remark here and there (usually once or twice per book) implying that real “Christians” believing in a Young Earth, this series is really pleasant and a family favorite.