Pushing others away from chalk
You would not like to be pushed so do not push others?
If you have more than one thing and others would like to play with them, then share them or offer to share them. If you have nothing to play with at the park and someone has two things to play with you would appreciate the thing to play with.
Sharing if there is more than one the thing can be shared easily. If there online one the thing an be shared by time of use.