Step1
Step2
Step3
Step4
When I achieve the Step3 I have just the the quantity in Step1 - quantity in Step3.
Step1: quantity = 10
Step3: quantity = 2
Total = 10 - 2 = 8
Is there some possibility ti calculate automatically the order with the other quantity (quantity = 8), without go to all steps. Just go from step 3 to step4?