When I was using scheme in class, I found it annoying to use the Scheme interpeter, make a bunch of mistakes and have a heap of error messages clogging the top part of the window. Traditionally, if this was done in the terminal, you could clear the screen with a command. In bash, everyone knows that clear clears the screen. Well, it does that in Scheme as well.
Just run (clear), as it is a procedure, you need the parenthesis.
This works in MIT Scheme. If you see a ;Unspecified return value, don’t worry about it. It simply means that the (clear) procedure returns nothing.