When there are more than one product on the order, it is useful to insert the product first, with the various additions, then use the handy numeric keypad to perform the four arithmetic operations of Division, Multiplication, Addition and Subtraction, on the quantities of the selected products.
To perform these operations, click on the numbers to set the quantity, then act on the desired operation keys, then press the Enter key (broken arrow). It is possible to perform operations with decimal quantities.

NOTE: by making changes to the ingredients on multiple products, the cost is multiplied by the quantities of the product.

Elimination of Products from Order.

To delete a product from an order, just select it from the list below of the Total to Pay, then use the Delete button (indicated by the green arrow).