M.B.
Long ago, (like 20 or more years ago?) my hubby used the chalkboard paint to paint a board we then hung up as a chalkboard for the kids... it worked great!!
If you are looking at making a "whiteboard", a lot of people (even schools) will take the much less expensive white shower wall liner and use that instead of the expensive true whiteboard. It doesn't clean up as well, though. Being plastic, it does eventually scratch and the dry erase stains it easier. You would probably want to "frame" it with quarter-round or some kind of molding (or floorboard trim) to keep them from accidentally coloring on the wall with dry erase markers.