Rule three is a process created to solve problems involving four values ​​of which three are known. Through the rule of three, we can calculate the unknown value, whether it directly or inversely proportional to the known values.
Steps to create a rule of three:
        a) Generate a table, with the quantities of the same species grouped in columns and the corresponding quantities of different species but the same line.
        b) Identify if the quantities in question are classified as either directly or inversely proportional.
        c) Generate the proportion and thus solve the equation.

The Application "Rule of Three" enables automatic calculation of three rule, requiring the user to only inform the classifying it as directly or inversely proportional and the known values.
From these data, the application generates the proportion and solves the equation rule of three.