Question

How do you count carbon atoms in organic chemistry?

Answer 1

The method used to count carbon atoms will depend on how the structure is represented.
The obvious answer first

If the molecule is written out in Lewis structure, meaning you can see every atom, just count your carbons.
While this sounds simple, I find that students get confused on exams, so I recommend using a highlighter or colored pen. Mark each carbon as you count it so that you can ensure no double-counting or omissions

If the molecule is written in line structure or skeletal structure, you will have to study this concept first to ensure that you know and understand what you're looking at.

Here is a video that teaches all about drawing/reading line structures

In short: Every angle, corner, intersection... represents a carbon atom. Use the highlighter trick mentioned above to count the carbons