From Wikipedia: A lap book generally consists of a paperboard folder such as a file folder with small pieces of folded paper glued inside. These folded papers may contain facts, diagrams, illustrations, etc. related to the subject. Lap books can be adapted for any subject and grade level. Teachers and parents who use lap books with students say that they enhance creativity and critical thinking while integrating subjects such as science, language, history, geography, and mathematics, depending on the subject of the lap book.
My brain cogs are spinning. The applications for Social Studies are obvious, but Math... ah, that's worth a bit of thought.
Write it on your communicator: Our Homeschool Style: Lapbooking.
Extra credit: Lapbook Lessons.