The abacus is considered the oldest calculating device used by humans but in the 1940s, a Korean man invented an abacus-like counting method using fingers called jisanbeop or chisanbop, a term that ...

If you have picked up an abacus from a thrift store and watched your toddler play with the beads, like I have, and wondered if that's all there is to it, read on. Using an abacus ("soroban"), that ...