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In the very beginning,when number system was not introduced,people knew the concept of counting.for example: A shepherd counted his cattle with the help of stones.But when their number increased it became very difficult to count them.He used the method to draw a line on land.But that way was also a difficult one.
Then number system was introduced.The number system consists of {1,2,3,4,5,6,7,8,9}.
But when this equation x+2=2 was solved,it was thought that their exist another number 0.so it was also included in that set and new set was known as the set of whole numbers.Also as time passed,new equation x+4=2 had to solve .From that equation we get the introduction of negative numbers .then rational and irrational numbers came to know.
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