One can not give the exact definition of number sense as it involves numbers and their relationship which is used in solving mathematical operations.

Number-system is classified into different types of numbers such as whole numbers, rational numbers, integers etc. If you see the history of mathematics there are different types of number-system, such as Egyptian system of numbers, Mayan system of numbers etc.

System of numbers begin at the age of two. From this age child is used to learn the numbers. The mother shows each number with the help of her finger, so that the child gets an idea of numbers through fingers. We are familiar with the word 'number' from kindergarten. As the child grows the mother and teacher explains the numbers through cards or by drawings. As the child grows the idea of numbers goes on increasing, due to different types of numbers such as whole numbers, roman numbers, rounding numbers etc.

Ask-math teaches you the number system step-by-step. Here we are trying to explain you the different types of numbers in detail. We also provide a worksheet to make your concept more clear.