This application lets you to calculate the unknown term of any kind of proportion including continuous proportions. To calculate a proportion check one of the four checkboxes to select the unknown term, enter the desired values ​​in the remaining fields and press "Calculate" button. To calculate continuous proportions you must check two checkboxes (the A and D checkboxes to calculate the extreme terms or the B and C checkboxes to calculate the central terms), enter the desired values ​​in the remaining fields and press "Calculate" button. To restore the application to the initial values ​​just press "Reset" button. The application also allows you to view the steps that lead to the solution.