# Real number

## Classification

Real numbers are classified as rational numbers (denoted by **Q**), integers (**Z**), whole numbers (**W**), natural numbers, and irrational numbers. In order of inclusion, non-irrational real numbers can be ordered as follows:

**Q**), integers (**Z**), whole numbers (**W**), natural numbers, and irrational numbers. In order of inclusion, non-irrational real numbers can be ordered as follows: