Hi Guys,
I am trying to create a tiered discount rate for our distributors.
it goes like this:

for 0-300 cartons 0 discount
301-700 3
701 - 1200 6
1201- 1800 8
1800 onward 10

This means that if someone sells 1300 units they get 0 discount for first 300, 6 for next 399, 8 for next 499 and so on. and then add the total discount they get to one cell.
What would be the way to go about this?
Really appreciate your help