This baby abacus was a hit with N (15 months)! Sliding the balls back and forth on the string took some practice and was great for her motor skill development.
As she moved each ball, we counted for her and that made her giggle. She also experimented with shaking the string and moving the chairs all around.
To make your own baby abacus for counting, moving, shaking, and experimenting, thread the string through a few plastic balls (4/$1 at the dollar store) and tie each end to a chair.