Abacus might have been quite replaced by a calculator by now. But actually, as far as the speed and preciseness are concerned, the abacus would quite surpass the calculator if it is operated by an experienced user. Soroban Japanese abacus, called ‘Soroban’ is made to be just simple; a number of rods lined in a rectangle frame. Each rod has 1 bead and 4 beads that are divided by a bar in between. A bead placed above the bar represents a number of five (5) and the each of 4 beads under the bar means a number of one ...