How do I round calculations to two decimal places (form-wide)

Hi,

I've created an order form where customers input the quantity of product they want to order and the form outputs the total due (including shipping and sales tax). Depending on user input, the resulting total sometimes contains more than two decimal places. How do I round calculations to two decimal places? Is there a way to do this form-wide?

I'm new at using Acrobat for calculations. Any help would be greatly appreciated! Thanks...