A pencil with a built-in speaker that changes pitch based on resistance!!? You will learn, in an interesting way, how you can ‘map’ different electrical devices to resistance in a circuit. You will surely enjoy building this novel ohm meter yourself and using it for tests. You can use it to investigate the difference between conductors and insulators, why some things can carry electricity, such as graphite, and some things are resistant to it, and how adding elements in a circuit changes its resistance. Among other things, the pencil allows you to create a hand-drawn working piano, be challenged to play songs, and use your body as a real electric circuit.