What type of numbers

As mathematics teachers, we need to know about the different types of numbers that we are dealing with. We introduce students to these gradually, and each new type comes with its own uses, and its own challenges. The main types of numbers used in school mathematics are listed below:. The first four of the above N , W , Z and Q are referred to as discrete. This means that they are separate and distinct entities. In fact each of these sets is countable. The last set, R , cannot be counted.

This is because they are continuous. Between any two real numbers, however close they may be, there are infinitely more real numbers. At higher levels of secondary and tertiary education discrete mathematics , is often more challenging than the mathematics of continuous functions. With continuous functions, a small change in the input variable leads to a small change in the output variable.

Natural numbers are counting numbers and whole numbers. They are 1, 2, 3, 4, Integers are positive and negative whole numbers. Numbers that can be written without a fraction. They are Rational numbers are numbers that can be represented as a fraction and some decimal numbers. D is always defined as not zero 0. If D is equal to one 1 , then it is an integer. Therefore, every integer is a rational number.

The set of all rational numbers is usually represented as Q. A decimal number is a rational number if it terminates has a finite number of digits or repeats a finite sequence of digits.