Total Price Problem With Discount Percentage

hi all,

Usually when a product (eg, $ 840) has a discount percentage (eg 1.75%) total order is unusual!


subtotal: 840$

discount (1.75%): 14.7$

Total: 825.3$

How should this problem be solved. Discounts and offers a total order to meet customer's favor.

As follows:

discount (1.75% Rounded): 15$

Total: 825$

This problem! I think it was more friends with.