Is it possible for a customer to enter data into one or two fields and have a third field calculate the value and immediately display for the customer to see?
Lot Size: 1000 Sq. Ft.
Salt melt area: 1 bag/500sq. ft
Bags of Salt Needed: 2 bags
So the calculated value will be the Bags of Salt, but the first entry is all that is needed. The Salt Melt area will be a default hidden value stored in the field.