What is a real number?

What Are Real Numbers?

Real numbers are one of the basic building blocks of mathematics. They are the fundamental units of measurement used to describe any possible quantity on a numerical scale. In mathematics, real numbers are the key subject of many theories and theorems, making them one of the most important concepts to understand.

Real numbers can be classified into three main categories; rational, irrational and transcendental numbers. A rational number is either an integer or a fraction, meaning it can be expressed as the ratio of two integers. Irrational numbers, on the other hand, cannot be expressed as a fraction, and are usually based on the square root of a number. Finally, transcendental numbers are those that cannot be derived from either rational or irrational numbers and are often found as solutions to equations or particular constants such as Pi.

Beyond this basic classification, there are further subcategories of real numbers. These include natural numbers, which are the count of whole numbers including zero; whole numbers, which are natural numbers plus zero; and integers, which are like whole numbers but can be negative.

Uses of Real Numbers

Real numbers are used to describe a great range of physical, mathematical and scientific phenomena. They are particularly important in calculus, where derivatives and integrals are based on the idea of understanding real numbers and their properties. In physics, real numbers are used to measure physical parameters such as mass, velocity and force.

In the world of programming and computing, real numbers are integral to representing values such as float and double, which are used in hardware and software calculations. Real numbers are also important in describing money, where rational numbers can be used to represent values such as currency and taxation.

Real numbers have their uses in everyday life too. They are integral to solving arithmetic problems such as addition, subtraction, multiplication and division, allowing us to go beyond whole numbers and apply fractions and decimals too. They are also used to represent mathematical shapes and figures, so we can understand the area and circumference of circles, the surface area and volume of cubes, and the angles and lengths of triangles.

Functions of Real Numbers

Real numbers can also be used to represent functions and equations, providing the ability to calculate how different values affect the result of an equation. For instance, equations like x2 + 4x + 6 can be represented by real numbers. This gives us the ability to quickly assess the values of the x and y co-ordinates on the graph of the equation and map out the shape generation.

Conclusion

Real numbers are everywhere, making them one of the foundations of mathematics and science. They are integral to representing physical and mathematical phenomena, but also for understanding everyday situations such as money and arithmetic. With their ability to represent equations and functions, real numbers provide the necessary insights into how different values affect the output of an equation, allowing us to map out intricate shapes and figures.