Variable in Math – Definition with Examples
Created on Dec 22, 2023
Updated on January 9, 2024
Welcome to another exciting exploration with Brighterly, where we make learning math fun and engaging! Today, we’re going to dive into a topic that is foundational yet fascinating: the variable in mathematics.
A variable in mathematics is like a treasure chest waiting to be unlocked – it’s a symbol, often a letter like x, y, or z, that holds an unknown value. Picture it as a secret agent in the world of numbers, taking on different identities depending on the mission. For instance, in the equation x + 2 = 5, ‘x’ is the variable, and we need to figure out its value to solve the equation. Variables are not just mere placeholders for numbers; they form the core of algebra and provide a way to generalize mathematical relationships and patterns. With variables, math transforms from a static set of numbers to a dynamic and universal language. Intrigued?
What are Variables?
In the captivating world of mathematics, one term that we come across frequently is “variable”. A variable is a symbol or letter, such as x, y, or z, that represents an unknown number. It’s a fundamental concept that allows us to solve equations, create formulas, and understand complex mathematical ideas. For instance, in the equation x + 2 = 5, ‘x’ is the variable. Here, ‘x’ is the mysterious character that we need to find to balance the equation! It’s fascinating how this single concept of variables creates a bridge between the abstract language of mathematics and the concrete reality. It makes mathematics not just a collection of numbers, but a powerful language to express and solve reallife problems.
Different Types of Variables
When we start to explore the universe of variables, we encounter various types, each with its unique properties and roles. There are dependent variables, independent variables, and constants – all of which help us create a more detailed picture of the mathematical world.
Dependent Variables
A dependent variable is a type of variable that changes in response to another variable, called the independent variable. In other words, the value of a dependent variable ‘depends’ on the value of the independent variable. Think of it like a seesaw: one side goes up (independent variable), and the other side goes down (dependent variable). In a mathematical equation, the dependent variable is usually the output or result. For example, in the equation y = 3x + 2, ‘y’ is the dependent variable because its value changes based on the value of ‘x’.
Independent Variables
An independent variable is the variable that is changed or controlled in a scientific experiment or mathematical equation to test the effects on the dependent variable. It’s the variable that stands on its own, uninfluenced by other variables. Going back to the seesaw example, the independent variable is the side that goes up or down by its own force – it does not rely on the other side to move. In the equation y = 3x + 2, ‘x’ is the independent variable.
Constant in Math
A constant is a value that does not change. In contrast to variables, which can represent different values at different times, constants remain the same throughout. For instance, in the equation y = 3x + 2, the number ‘2’ is a constant because its value doesn’t change, regardless of the values of x and y. Constants provide stability and allow us to understand relationships between variables more clearly.
Parts of Equation
In a mathematical equation, there are several parts, each playing a unique role. There’s the lefthand side (LHS) and righthand side (RHS) separated by an equals (=) sign. Variables, constants, coefficients (the numerical factor of a variable), and operators (+, , x, /) all form parts of an equation. For example, in the equation 3x + 2 = y, ‘3x + 2’ is the LHS, ‘y’ is the RHS, ‘x’ and ‘y’ are variables, ‘3’ is the coefficient of x, ‘2’ is a constant, and ‘+’, ‘=’ are operators.
Variable in Statistics
In the realm of statistics, variables hold a special place. A variable in statistics is an attribute that describes a person, place, thing, or idea. The value of the variable can change from one entity to another. For instance, age, height, weight, and income are all examples of variables in statistics. They help us to collect, analyze, and interpret data, which then allows us to make informed decisions or predictions. Two main types of variables in statistics are categorical variables (which have categories or groups) and numerical variables (which are expressed in numbers).
Types of Variables in Math
Apart from dependent, independent, and constant, there are other types of variables in math as well. Let’s explore some of these:

Discrete Variables: These are variables that can only take certain values. For example, the number of students in a class can only be a whole number.

Continuous Variables: These are variables that can take any value within a given range. For example, the height of a person can be any value within the possible range of human heights.

Random Variables: These are variables whose possible values are outcomes of a random phenomenon. For instance, the result of a dice roll is a random variable because it can be any number between 1 and 6, each with an equal chance.
Solved Examples on Variable
To better understand the concept of variables, let’s walk through some examples:

Example 1: Solve for the variable x in the equation x + 5 = 10. Here, by subtracting 5 from both sides, we find that x = 5.

Example 2: In the equation y = 3x + 2, find y when x = 4. By substituting x = 4 into the equation, we find that y = 3*4 + 2 = 14.
Practice Problems on Variable
Now, it’s time for you to practice! Try solving these problems:

Solve for x in the equation 2x – 3 = 7.

In the equation y = 2x – 1, find y when x = 3.
Conclusion
As we wrap up our journey with variables on Brighterly, we hope you’ve discovered just how instrumental these mathematical agents are. They are the unsung heroes that enable us to express, explore, and solve a broad range of mathematical problems. The beauty of variables lies in their versatility and ability to make math more abstract, universal, and applicable to reallife situations.
The world of variables is vast, with different types such as dependent, independent, and constant variables, each playing unique roles. Understanding these types and their interactions is akin to learning the grammar of the language of mathematics. It’s a critical step in your math learning journey.
Remember, like any new language, becoming proficient in using variables requires consistent practice and application. The more you engage with variables, the more comfortable you’ll become, and the more mathematical doors you’ll be able to unlock!
At Brighterly, our mission is to illuminate your path to mathematical understanding. We believe in learning that’s engaging, interactive, and, most importantly, fun! So, keep exploring, keep asking questions, and keep growing your mathematical knowledge. After all, with variables in your toolkit, the possibilities are endless!
Stay tuned for more math adventures with Brighterly! Because learning math is not just about numbers, it’s about brightening your world with knowledge, one concept at a time.
Frequently Asked Questions on Variable
What is a variable in math?
A variable in math is a symbol or letter, such as x, y, or z, that represents an unknown number. Variables are crucial components of algebraic expressions and equations, allowing mathematicians to generalize relationships, patterns, and rules. They enable us to model and solve realworld problems, making math a powerful and versatile tool.
What are the types of variables in math?
There are several types of variables in math, each with distinct characteristics and applications:
 Dependent Variables: These variables change in response to another variable, called the independent variable. They are usually the output or result in a mathematical relationship or equation.
 Independent Variables: These are variables that are changed or controlled in a scientific experiment or mathematical equation to test the effects on the dependent variable. They are not influenced by other variables.
 Constant Variables: Constants are values that do not change and remain the same throughout a mathematical relationship or equation.
 Discrete Variables: These variables can only take certain values, usually whole numbers or integers, and are often used to represent countable quantities.
 Continuous Variables: These variables can take any value within a given range and are used to represent measurable quantities that can vary continuously.
 Random Variables: These variables represent the possible outcomes of a random phenomenon, such as the result of a coin toss or a dice roll.
What is the difference between a dependent and an independent variable?
The primary difference between a dependent and an independent variable lies in their relationship with each other:
 A dependent variable changes in response to the independent variable. Its value “depends” on the value of the independent variable. In a mathematical equation or scientific experiment, the dependent variable is typically the outcome or result being measured.
 An independent variable is not influenced by other variables. Instead, it is the variable that is manipulated or controlled to determine its effect on the dependent variable. In a mathematical equation or scientific experiment, the independent variable is the input or factor being adjusted.
What is a constant in math?
A constant in math is a value that does not change. Unlike variables, which can represent different values at different times or under different conditions, constants remain the same throughout a mathematical relationship or equation. Constants provide stability and help us understand the relationships between variables more clearly. Some wellknown constants include the number pi (π), which represents the ratio of a circle’s circumference to its diameter, and the speed of light in a vacuum (c), which is approximately 299,792,458 meters per second.