The correct option is D Both statements 1 and 2 are true and 2 is not the correct explanation for 1.
The ancient Chinese invented the abacus and used it for calculations. They called it Suanpan. It was required because the Chinese number system was multiplicative. Basically, the number is a multiple of the largest unit followed by the next largest unit and so on. For example, to write 500, they would write the characters for 100 and 5. The Suanpan consists of seven rods with two beads on each rod in the upper deck and five beads in the bottom deck. The beads are counted by moving them up or down towards the beam.