Whole Numbers

      Natural Numbers are the numbers that we use to count: 

                       = {1, 2, 3, 4, 5, 6, 7, …}

  When we add number zero and the negative numbers to the Natural Numbers, we obtain the Whole Numbers:

                     = {…, -4, -3, -2, -1, 0, 1, 2, 3, …}

and we represent these numbers in a straight line: