I am confused on when to apply note 3 vs. note 4 in table 220.55? If I have one cooktop and 1 wall mounted oven do I use note 3 and add all together and use derating of each, or do I use note 4 and add together and use as 1 unit? Any thoughts on this? I am preparing for the NEC exam and need to know how to answer the questions for the test. I am taking this exam in 1.5 wks and need to clarify this for the practice.