How many Let's Find Out About Simple Machines books are there?

There are 2 books in the Let's Find Out About Simple Machines series by Martha E. H. Rustad, for ages 4-8.

Let's Find Out About Simple Machines Books in Order

2 books · Ages 4–8 · Chapter Books

Let's Find Out About Simple Machines is a 2-book series for ages 4–8 by Martha E. H. Rustad. Each book stands alone — start anywhere.

Start anywhere — each book stands alone.

That said, Inclined Planes and Wheels and Axles are great first picks.

No particular order needed — browse and pick what catches your eye.