Older books (copyrights in the 1990's) helpful for homeschooling and education.  They are AIMS Activities (Activities Integrating Math and Science) - for grades K-3 there is Primarily Earth and Primarily Physics.  For grades 2-4 is Bats Incredible! and Under Construction. 2 of the books have a cutout on the cover (where prior owners name was written in marker).  Otherwise they are in nice condition.