Numbers are an essential element of our everyday thought and language. In present-day life, every activity requires the use of numbers. Prices and weights of commodities, measurement, scores of games, travel time tables, etc., are all expressed in numbers.

• Points on a straight line are unconnected to others as it is a different concept of points. It is NOT related to rational numbers and integers.
• The first numbers to be discovered were natural numbers i.e. 1, 2, 3, 4,... If we include zero in the collection of natural numbers, we get a new collection of numbers known as whole numbers i.e. 0, 1, 2, 3, 4. The new collection of numbers will look like 0, 1, 2, 3, 4, 5,..., –1, – 2, – 3, –4, –5, ... and this collection of numbers is known as Integers.
• Numbers which can be expressed in the form - where p and q are integers and q # 0 are called rational numbers. 
• Rational numbers and Integers both are connected to each other.

Thus, it is not concluded that Points on a straight line are unconnected to others.