Materials: copper sheet, mirror paper, wood, wire, 9 volt battery, buzzer, something with a pointed metal tip, duct tape.

Building Instructions: Cut shape out of copper sheet. Drill holes through both pieces of copper sheet. Screw wire into both pieces and attach wires to the red wire of the buzzer. Attach negative terminal to black wire of buzzer and attach pointed metal tip, which will be used as a tracer to the positive terminal of the 9-volt battery. When tracer touches copper sheet the buzzer should buzz. Mount mirror paper on back of the box.

Function and Use: We are all familiar with mirrors and you probably remember that mirrors make things look upside-down and backwards. These boxes test your ability to translate mirror images to real images and trace out a pattern. Looking through the top slit in the box you will see a mirror image of either a star or a smiling moon. Your job is to use the pointer to trace out the pattern in the gaps between the inner object and the outer object using only that mirror image. If you touch the inner or outer image a buzzer will sound. Good luck! How did you do?