Variables in math are symbols, often letters, that represent different values in various situations. They help us understand and solve problems with changing values.

To use a variable, we must both declare it—to let the program know about the variable—and then assign it—to let the program know what value we are storing in the variable.

Variables in math are symbols, often letters, that represent different values in various situations. They help us understand and solve problems with changing values.

In programming, a variable is like a box where you can store information (like a number or a word). This information can be changed later on (whereas a constant keeps the information it was assigned to …

In algebra, we use variables like x, y, and z to represent unknown values. Expressions are combinations of variables and numbers, while equations equate two expressions.

Practice Writing basic expressions with variables Get 5 of 7 questions to level up!

Many studies and surveys consider data on more than one variable. For example, suppose a study finds that, over the years, the prices of burgers and fries have both increased.

We learn how to calculate the mean and standard deviation of a discrete random variable. The concept of a random variable is explained, along with methods to calculate its expected value (mean) and …

For a variable to be binomial, does each trial need to have the same probability of success, or is it enough that each trial has an independent constant probability of success?

A single quantity should be represented by only one variable, so you should not have two different variables used for the same thing. So if a question talks about finding Andy's age, you cannot use a …