The abacus is an ancient form of calculating tool also known as a counting frame. While the exact origin of the abacus is unknown, early frames probably didn't include letters formed in the QWERTY keyboard style as seen on this shirt.
The abacus t-shirt design here features a fantastical abacus framed inside of what looks like a computer monitor. There is even a corded mouse attached to the frame. The rows of beads, used to represent numbers on an abacus, appear here with numbers written on them, as well as letters as you'd find on a modern QWERTY keyboard.
This QWERTY B.C. t-shirt is fun for math nerds, computer geeks, and others interested in the abacus and its different forms. Available from Zazzle, this design can be purchased on a huge variety of apparel styles and other novelty gift items in Zazzle's catalog.