How many Simple Machines books are there?

There are 4 books in the Simple Machines series by Helen Frost, for ages 4-11.

Simple Machines Books in Order

4 books · Ages 4–11 · Early Readers, Chapter Books

Simple Machines is a 4-book series for ages 4–11 by Helen Frost. Each book stands alone — start anywhere.

Start anywhere — each book stands alone.

That said, Let's Find Wedges and Levers are great first picks.

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