Calculator for finding a number in the same ratio to a given number as exists between two other given numbers With this App you can calculate Rule/Method of Three in a way that you wish, by percentage, whatever! And doesn't matter the field, it shows the result in any field. This App calculates proportions (direct), also known as "rule of three" by entering three known values and hitting "Calculate". The App will calculate the missing value for you! The Rule of Three is a Mathematical Rule tha