Chalkboards are also good visual aids for small audiences, if you follow these hints:
Always check the chalkboard ahead of time to make sure the legs and pegs are stable.
Have plenty of yellow chalk available, and keep a spare piece in your pocket. Yellow shows up better than white.
Use damp, not dry, dusters.
If you use a pointer, don't let it waver around the board. Point at what you want to emphasize, leave the pointer there for a moment, and then take away the pointer.
Never try to draw or write for more than a few seconds at a time; avoid talking while you're drawing. When you want to explain what you're doing, turn and face the audience before speaking.
Clear the board as soon as you're finished with what's on it and have moved on to a new topic. Old drawings will distract your audience.