How was trade done earlier ?

The Stone Age man was not aware of any trading. They hunted for their own requirements, later they started cultivating fields. When the wild animals became scarce in a particular area of the crop was bad, tribes moved forwards. Eventually, people cam across the other groups that cultivated and produced different things - an exchange of goods started. For the exchange of goods, the value of the goods had to be determined . This could not be done without numbers, measures, and weights. Scales and calculating devices such as the Abacus were invented, the trading activity expanded and a real triangular trade arose

Who invented the numbers ?

The first written number system is about 5000 years old and comes from the Sumerians in Mesopotamia. But man wanted to specify quantities even much earlier: of the animals killed or of mushrooms. In the beginning, man counted using the finger joints on each hand. Even today, young children are taught to count on their fingers. It is known about the Stone Age man that he used tallies by cutting notches in wood, bones, and stones. Similar tally sticks were even used in England till the 19th century.

How does an abacus work ?

Abacus is the most ancient tool used for the purpose of calculations. It consists of a frame with rods or wires, on which spheres are beaded. The value of the spheres depends on the rod, on which they are beaded: units, tens, hundreds, and so on. By moving the balls on can do the four simple mathematical operations as well as more difficult calculations. the result can then be read from the position of the balls. Abacus is used even today in some countries of retailers, such as China and Russia.