Advanced math/making a calculator

Is there some way to, without database input, in an app that does not require any signup or login to make a calculator for the approx. cost of changing a roof?
It should go like this:

  1. Dropdown with 4 choices.
  2. A slider/input where you enter amount of squaremeters
  3. A question if you would like to change the woodwork around the roof.
  4. if yes, then an input/slider that you enter the ongoing meters.
  5. if no then leave out point 4.

The math would be like this:
choice from 1 will multiply input from 2 depending on choice 1-4 (could be that choice 1 will multily by 1200, and choice 2 will multiply by 1500 etc.)
then if 3 is yes, + (200 * input/slider) to above and a result will come out. if 3 is no, then display the result without 4.

so example, where choice in 1 is 1, input in 2 is 100 and 4 is activated and input there is 200, the math would be like this:
(1200 * 100) + (200 * 200) = 160.000