What is a Rational Number? Definition and Rational Number Example

A rational number is a number that can be expressed as a ratio of two integers. In other words, a rational number is any number that can be written in the form of p/q, where p and q are integers and q is not equal to 0.

For example, 2/3, -5/7, 1/2, and 3 are all rational numbers. On the other hand, irrational numbers cannot be expressed as a ratio of two integers. Examples of irrational numbers include pi (3.14159265…), the square root of 2 (1.41421356…), and the golden ratio (1.61803398…).

Rational numbers can be positive, negative, or zero. They can also be expressed as decimals, but the decimal will either terminate or repeat. For example, 2/5 can be written as 0.4, which terminates, while 1/3 can be written as 0.33333…, which repeats.

Rational numbers can be added, subtracted, multiplied, and divided just like any other number. When adding or subtracting rational numbers, you simply add or subtract the numerators and keep the same denominator. When multiplying rational numbers, you multiply the numerators and denominators separately. When dividing rational numbers, you multiply the first rational number by the reciprocal of the second rational number.

Rational numbers are used in many different areas of mathematics and science, such as geometry, statistics, and physics. They are also used in everyday life, such as when measuring ingredients for a recipe or calculating the distance between two points.

In conclusion, a rational number is any number that can be expressed as a ratio of two integers. They can be positive, negative, or zero and can be expressed as decimals that either terminate or repeat. Rational numbers are an important concept in mathematics and science and have many practical applications in everyday life.