Looking for a great and inexpensive costume for Halloween, Pi Day, or Math Night? Use these quick and easy templates to print adhesive decals that will turn any shirt into an inexpensive, wearable calculator costume. Thirty templates of the calculator keys cover all the basic operations and many more. Two screen templates are also provided – one blank one that you can fill in and one with pi rounded to 15 decimal places. By downloading one of my math tricks handouts such as “Algebra Man” or “Mystery of the Icons”, you can impress your students as the Human Calculator.