Number Box

This construction, consisting of rows of pellets set onto colorful pins, once allowed Ni-Kunni mathematicians and natural philosophers to perform highly complex calculations. Its use faded into memory, as most things do, only to be rediscovered as a tool with which to teach students the particulars of certain highly abstract three-dimensional calculations required for space flight.

The number box's pins are placed both horizontally and vertically, so the pellets can be slid along a triple axis; the box is also, to the relief of some teachers, heavy and solid enough to hit a student firmly over the head if he still can't grasp the math.