In English, the phrase "看黑板" is typically translated as "look at the blackboard." This phrase comes from the common practice of writing on a blackboard in a classroom setting. Here are some example sentences and their translations:

"Please look at the blackboard while I explain the concept." (请看黑板，我解释一下这个概念。)

"The teacher wrote the homework assignment on the blackboard." (老师把作业写在黑板上。)

"I can't see the blackboard from the back of the room." (我在房间后面看不到黑板。)