## Numbering

Michelle Choi 1H
Posts: 8
Joined: Tue Nov 17, 2015 3:00 am

### Numbering

For numbering the carbons, you don't sum up the the individual numbers for every substituent right? For example, if you had to choose between 1, 2, 5 and 1, 3, 5 you would choose the first numbering because 2 is less than 3 and not because 8 is less than 9 (which is the sum of both sets respectively)?

Laura Picazo 1L
Posts: 16
Joined: Fri Sep 25, 2015 3:00 am

### Re: Numbering

That is correct. You want to use the lowest number possible, and not necessarily the sum. Sometimes, the nonexistent "sum rule" does work out, like in the case you have described.