I wanted to come up with a variant of Chisanbop but using the familiar STS signs (which I already use for keeping track of the guess count when playing 20Q). It’s not STS counting exactly since one hand would be keeping track of the units and the other the tens.

It was a flop because Chisanbop’s bi-quinary system is exactly analogous to soroban counting making a lot of operations straight-forward using the complements table. That doesn’t work at all with STS’s notion of six seven eight.

Counting in STS sign language (incompatible with ASL and ESL).