This is a known bug.
You have to type .0 into the calculator manually. This seems to initialize the calculator for decimals in foxuser.dbf. After that it will work according to your SET DECIMALS.
>Why is the calculator rounding and how can I get it to display the correct value? When I do this:
>
>_calcvalue=1234.56
>ACTIVATE WINDOW calculator
>
>I see 1235 on the calculator.
>
>Thanks,
>Elyse