A number line is defined as a straight line with numbers placed at equal segments or intervals along its length. A number line can be extended infinitely in any direction. The numbers on the number line increase as one moves from left to right.
All three numbers 2, 3 and 5 are on the right side from zero at the number line. The distance from number 2 to zero is 2, the distance from number 3 to zero is 3 and the distance from number 5 to zero is 5. If all numbers are placed in one side from zero, then you can compare them by theirs distances. Since number 2 is the nearest to zero and number 5 is farthest from zero, you can conclude that 2<3<5.