number format

Hi there,
I have two form fields that I've defined as a Decimal with 2 decimal values each. One of the fields is automatically calculated as (input.price_a = input.price / 6)
Unfortunately when this operation is performed I get a number with 10 decimal values in the price_a. Is there any way of formating the result of the calculation in order to add a double with two decimals in input.price_a?

Thanks very much in advance for your time...

Luis Pedro