What Is Variable In Math? – An Absolute Guide For Students

What is variable in math, and why do variables call variables? These are some of the questions that are asked and searched by the students. That is why I am here to help those students with the best and complete guide on what is a variable in math.

Before moving to the details, I would like to make you understand the word “variable.” Well, as the name itself suggest, 

‘vary’+’able’ = variable 

That means the thing that has the ability to vary or change as per the condition. 

But in the case of a variable in math, the operation applied to a variable remains the same.

Finding this information quite interesting?

Let’s move to the details about what is variable in math and other interesting information related to variables.

What is a variable in a math problem?

A variable is any letter or alphabet that is used to attain a specific number. You can use any of the English alphabets such as A, b, c, x,y, p, Q in lower or upper case to represent a variable. 

Key point:
It is important to note that the letters e and o are not used as the variables. As e is used for Euler’s number that is equal to 2.71828. On the other hand, o is not used as it might consider as 0 (zero) by mistake in an algebraic expression.

The variable in math is also used as the function as it represents many numbers rather than just a single constant number. Moreover, it has been seen that variables are useful to understand the problems of various graphs.

See also  Top 10 Importance of Mathematics in Everyday Life

Let’s take an example of a variable:

Einstein’s famous equation that is E = MC^2 that use variables:

  • E to represent the value of energy produced.
  • M represents the value of mass used.
  • C^2  is the speed of light squared.

Now the question is, why is the variable called a variable?

The simple and correct answer to this question is that variables represent information that can change. But on a note that the operation applies to the variable remains the same. 

In other words, we can say that variables are the unknown variables or quantities that are opposite of the constants. The constant variable is the unchanged amount that remains fixed throughout the calculation.

What are the 3 types of variables?

Once you get familiar with what is variable in math, it is necessary that you must know the types of variables too. In mathematics, basically, there are three different types of variables. But it has been seen that two types of variables are used the most. That is the dependent variable and independent variable

Both these variables are used in statistical studies to control the outcomes of an experiment.

Suppose you have the algebra equation or linear equation as y = (x)^3 (x to the power 3 or x cube). Here, y is a dependent variable that depends on the value or the function of x^3. On the other hand, x is the independent variable as its value can change as per the different conditions.

Apart from these, there is another type of variable that is a controlled variable. Control variables are considered fixed or constant throughout the complete scientific experiment. 

See also  Tutorial on How to Solve The Exponential Equation

Like, the temperature is the controlled variable that needs to be constant in an experiment. But if you need to take different observation values at different temperatures, you can easily change or control them as per the need.

Are variables in computer programming the same as that of mathematics?

No!! Not at all.

The variables in computer programming are assigned to be a data type, such as alphabet, array, numeric, image, or video clips. Therefore, you must know what is variable in math and what is variable in computer programming.

The variables are used for assigning the memory location. The data at different locations can vary at the time of execution of the programs. 

But whenever the variable is encountered within the program, the computer can substitute the information at the right memory location for the specialized variable.

How do you define a variable?

If you really want to know what is variable in math, you also know how to define a variable in math. The variables are used for changing the given verbal expression or statement into the algebraic equation. 

The algebraic equation is made up of a letter(s), number(s), and some of the operation keywords. The keywords are useful for translating words into the numeric equation. And these keywords are for:

Division: divided by, halves, ratios, and so on.
Multiplication: products, of, time or times, multiplied of, and so on.
Sum: greater than, more than, increase, sum, addition, and more.
Subtraction: smaller than, less than, decrease, minus, and more.

Also Read

Let’s take some of the examples to understand how to define the variable:

  1. y is divided by 5.
  2. 4 times of variable x.
  3. The p variable minus 11.
  4. The addition of a variable z and 2.5.
See also  Geometry vs Trigonometry | What is the Best Between Them


4*x => 4x.
p -11.
z +2.5 or 2.5 +x.

This is how you can define the variable statement into an algebraic expression. To know what is variable in math, let’s define the variables from the above mathematical expressions.

y is the variable.x is the variable.p is the variable.z is the variable.

Is it possible to find out the value of a variable(s) of an algebraic equation?

Yes, it is possible!!


Let’s check the method to calculate the value of the variable(s).

Here, we have used two different methods: a direct method and the substitution method.

Direct method

In this method, you have a variable with some mathematical operators. For instance, x + 5 = 11.

How to solve this: 

=> You can simply take 5 to the right-hand side by changing the operator sign.
=> Now, the equation will be x = 11 – 5. Subtract 5 from 11, and it will give 6. That is x = 6.
=> It means x variable has the value 6.

Substitution method

In this, you are provided with two or more variables. You have to substitute a variable value in the equation to get another variable value.

How to solve this: 

Suppose you have the equation x – 2y = 8 and x = 5 – y. Here, you can substitute the value of x in x – 2y = 8.
It will look like (5-y) – 2y = 8 => 5 – y – 2y = 8.
Take variables on either side and constants on the other side.
– y -2y = 8 – 5 => -3y = 3.
-y = 3/3 => -y = 1 or y = -1.
Now, put the value of y in x = 5 – y to find the value of x.
x = 5 – (-1) => x = 5 + 1 => x = 6.
It means x and y have the value (6, -1) for the above equation.

This is what is variable in math and how to calculate the value of variables in algebraic equations.


A variable can be a symbol or a single letter that defines an unknown value. And variables are represented by any alphabetic letter except e and o. 

Moreover, I have detailed all the necessary information on what is variable in math in the above sections. If you still have any queries, please let me know through your comments.

Apart from this, if you want to know any mathematical concept, comment it in the comment section. I will definitely be going to provide you with a detailed guide on that particular topic. We have the best answer for your question i.e. I need help with my math homework. Grab it now to clear all your mathematical concepts.

“Keep in touch with STATANALYTICA to master mathematical concepts.”

Frequently Asked Questions

What is variable answer?

A variable answer is a letter or arithmetic symbol whose value is not fixed. Its value varies depending on other parameters. For instance, 1,2,3, or any number or a,p,r, or any word can use as a variable.

Which variable do you keep the same?

Controlled variables are taken the same throughout a scientific experiment. If you make any change in any of the controlled variables, then the result would cancel.

What are variables in statistics?

A variable is any number, or characteristics, or quantity that can be counted or measured. Moreover, a variable can be a data item, such as age, business income, birth rate, capital expenditure, eye color, class grades, and vehicle type are the examples of variables.