Years ago when I was a brand new teacher I observed Mr. Danger. I always saw his students fighting to go to the board and I was determined to learn his secret, a secret I learned within 5 minutes.
Mr. Danger gave his class "B's" every time they picked up the chalk. They loved the "B's" and worked hard to get them.
When the class ended I asked Mr. Danger what he did with all the "B's" the students collected. He just laughed and said he did not do anything and the students knew it. Mr. Danger was funny, full of life and he loved teaching and his students. The "B's" were just a way to pass this enthusiasm to his charges and it worked. His students were very successful.