Motor skills and hand-eye coordination.
Creative and divergent thinking.
Sometimes having blocks out all the time is hard work because even though the blocks look great in the box they do not look so great spread out all over the floor. Just think though, of all the learning that takes place between the blocks in the box and the blocks spread all over the floor.
Be inspired. Let the children play. And learn.
My grand-daughter at play, at work. 3 yrs, 10 mos.