Look at the blackboard, everyone.

Our math teacher drew a circle on the blackboard.

I found out that advances in science rarely come upstream from an ability to stand at a blackboard and conjure images from unfolding mathematical propositions and equations.

Although only a minor hit when first released, when used in the opening sequence of the movie Blackboard Jungle a year later, it set the rock and roll boom in motion.

And it's the dilemma that this Chinese man faces, who's language is spoken by more people in the world than any other single language, and yet he is sitting at his blackboard, converting Chinese phrases into English language phrases.

I was looking for a picture of graffiti, little text input language, and I found the website dedicated to teachers who want to make these, you know, the script writing things across the top of their blackboard, and they had added graffiti to it, and I'm sorry about that.