MS Access form module/formula to multiply field by a variable

I have a database of elect components. For capacitors the database wants value to be numeric. So for a 0.01uF the table wants to see 0.00000001. I am not good at counting zeros, I want to enter in the form fields | 0.01 | u | and the resulting field to be |0.00000001| using an if else statement for p(ico) and n(ano) values. Do I do this in a form or a query? Not sure of where to start.