blackboard

noun, a board with a smooth dark surface used in schools for writing on with chalk (COD)

“You’d almost have to stand on the chalk ledge to reach the top of the blackboard.”

“Every day somebody had to clean off the blackboards.”

“Yeah, chalkboard or, yeah, we called it the blackboard.”

“We’d have to stand on a chair to reach the top of the blackboard ’cause the whole front of the school was blackboards.”