Oh i got it. You will go with maths. Yet, you should have in mind that you are holding an 8-bits PIC. Maths will be a little bit more complicated, as you only have add and sub functions. I strongly suggest you visit the section that i have with code snippets, in which you will find functions for division and multiplication. The URL is:

All about PIC microcontrollersDo not try to do this alone. Also, try not to use decimal numbers. For example:

value / 512 x value / 0,14

I would convert it to

value / 51200 x value / 14

and of course i would have multiply the value by 100. Also, prefer to multiply or divide by powers of 2. For example, instead of multiplying all nymbers by 10, you can multiply them by 64. The number 0.14 will be 8.96, which is actually very close to 9. The error in calculations would be as if you had divided instead of 0.14 with 0.140625, which is very small.

I tell you this, because the multiplication with powers of 2 can be achieved easily, simply by shifting the bits of a register left (to multiply) or right (to divide).