ok, heres the problem, I can use calculation to add up other numbers in a form, but now i want to insert that number in to a record, I did it once but i can't find the database i did it in to jog my memory.
I would do this in VBA. Simply put you create a text box on the form that your doing the calcuation in and link it to the record you want. Then perform your calculation and set the textbox value to the results. See below.
using VBA:
Sub Calc()
Dim Calc As Integer
Dim Val1 As Integer
Dim Val2 As Integer
'Just to signify a calculation...
Calc = Val1 * Val2
txtFieldOnForm.Value = Calc
End Sub
This is very rough and lacks any error handling that you would need but it should get you started.