Within Other Settings you can control the way in which Supplier Orders can be raised in Workbooks and how discount is applied to customer transaction line items.

Strict Supplier Orders

By default, Workbooks only allows you to create line items on Supplier Orders if the product you've entered on the line item has been linked to that supplier via the Supply Schemes tab on the product.

If you want to relax this setting you should navigate to Start > Configuration > Database > Other Settings and remove the tick from the checkbox next to Strict Supplier Orders.  Removing this tick means it is possible to raise Supplier Orders with any combination of Suppliers and Products.

Discounting Line Items

By default, when you apply a discount to a line item in a customer transaction record, the discount is applied to the unit price and this reduced price is multiplied by the quantity to generate the line item net amount. For example:

(Unit Price minus Percentage Discount) multiplied by Quantity

eg, £3.85 - 50% = £1.93 * 15.4 = £29.72

To deal with changes in monetary values caused by decimal rounding issues, you might want discount to be applied after the unit price has been multiplied by the quantity.  For example:

(Unit Price multiplied by Quantity) minus Percentage Discount

eg, £3.85 * 15.4 = £59.29 - 50% = £29.65

To apply the discount after the unit price has been multiplied by the quantity, make sure you remove the tick from the checkbox next to Apply discount before total.