An independent variable is a variable that is manipulated to determine the value of a dependent variable. The dependent variable is what is being measured in an experiment or evaluated in a mathematical equation and the independent variables are the inputs to that measurement.
In a simple mathematical equation, for example:
a = b/c the independent variables, b and c, determine the value of a.
Here's a simple example:
A teacher wishes to compare the number of tardy students wearing black with the number of tardy students wearing pink. In this scenario, clothing color is the independent variable and the difference in the number of students, categorized by clothing color, is the dependent variable.