Get to work cleaning the blackboards, Billy.

(f) Be sure you have means of cleaning the blackboard: a duster or an eraser.

I knew he was thinking he would soon have back his old job of cleaning the blackboard erasers for Miss Deets.

He recommends teaching children chores like cleaning the blackboard or taking out the trash at home, volunteer services and nonpaying jobs for which they get extra credits or allowance.

If you re-enter the room before Einstein has finished his sentence, still keeping the teacher out of sight, the teacher will - instead of issuing lines - turn around, start cleaning the blackboard, continuing to wipe the wall, then will walk through the wall on the far left-hand side.