2 books · Ages 3–7 · Chapter Books
Math Counts is a 2-book series for ages 3–7 by Michael Dahl. Each book stands alone — start anywhere.
Start anywhere — each book stands alone.
That said, Eggs and Legs: Counting by Twos and Hands Down: Counting by Fives are great first picks.
No particular order needed — browse and pick what catches your eye.