When did you first start using an abacus?
You probably used it when you were in school or college.But if you didn't, you probably still use it for some work today.Now, the word 'abacus' has become synonymous with all kinds of things that you don't normally associate with an object.But, it was actually invented in 1723 by Johann Georg Bernoulli, a French chemist.Bernoulli made the first modern abacus in 1730, and by 1750, it had become a...