Rounding Up of figures


is it possible for a sales order line to round up to a different decimal place rather than the standard decimal rounding up?

Example, a particular sales order line is calculating its net amount based on 3 decimal Unit price (0.556) whereas all order sales order lines are calculating based on 2 decimal places. The Unit Price for that specific Sales Order Line is displaying a figure rounding up to 2 decimal places (0.56) but doing the calculation based on 3 decimal places (0.556).