Numbers on a line is called the representation of whole numbers on number line.
The number line also helps us to compare two whole numbers, i.e., to decide which of the two given whole numbers is greater or smaller.
In order to represent whole numbers on a number line, we draw a straight line and mark a point O on it.
Starting from O, mark points A, B, C, D, E, F, G, H, etc. on the line at equal distances to the right of O.
Label the point O as 0.
Let us take OA = 1 unit. Then, AB = BC = CD = DE = 1 unit.
OB = OA + AB = (1 + 1) units = 2 units,
OC = OB + BC = (2 + 1) units = 3 units,
OD= OC + CD = (3 + 1) units = 4 units and so on.
Since O corresponds to the whole number 0, therefore, A, B, C, D, etc. correspond to the whole numbers 1, 2, 3, 4, etc. respectively.
The arrow marks on both ends of the line indicate that the number line extends indefinitely on both sides.