In this project, students create their own "Mathemagic" trick and prove why it works. A very simple example would be "Choose a number, add 3, double it, subtract 6, divide it by 2. You'll get back your original number." You can easily adjust this assignment to fit different levels, from beginning algebra to advanced, by changing the operations students must use, and focusing more or less on the idea of a domain on which the trick works.
Common Core Standard(s):
A-REI.1 Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
A rubric is included.