I like exploring all the possibilities available using a certain medium. In the case of Chalk, here are a few possibilities to explore:
Trace around shapes – triangle, square, hand, foot, ball.
Drag a piece of chalk behind you to make a snail trail and see where you have been or even better get your little charges to follow your footsteps.
Pop a piece of chalk into a balloon, blow it up and use it as a drum.
“Cook” with some chalk pieces – 5 fat sausages sizzling in a pan is a good nursery rhyme to sing for this game.
Build a town with blocks and add some chalk detail to it.