Counteen

A numerical system with any number <20 reverts back to the numbers 10-19 and adds a "teen" according to the value of the corresponding number.
Example: 20 would be 10T (pronounced "ten teen.") 25 would be 15T. 35 would be 15TT (fifteen teen teen,) and so on.

Math has never been so clearly written on paper until I found out Counteen!

by sheetmusicsman June 01, 2021