The teacher’s calculator inspired one of his students. Kale_3D not only repaired that broken calculator (he was the only one in his class to do it), he made one of his own. His gadget, an improvement over Gabe’s basic calculator, can accommodate more digits, has trigonometric functions and can also perform complex algorithmic calculations. It uses an Arduino compatible LCD screen with LED backlight, a 9v battery as power source, a suitable USB cable, Arduino duemilanove, a computer and a lot of wiring.