https://www.pcgamer.com/check-out-this-coaster-calcuator-built-in-rollercoaster-tycoon-2/

An enterprising soul has designed a calculator from rollercoasters using Rollercoaster Tycoon 2’s creative toolset. YouTube user Marcel Vos posted the above video demonstrating the calculator in action, which uses a pair of trains running along a labyrinthine track setup to input two numbers and output the resulting calculation.

The video shows off three calculations performed by the gigantic coaster, multiplying 2 and 8, multiplying 7 and 7, and adding 1 to 1.