In that case, instead of the die, we have the tri. And so we have hexadeca trinoic acid, 16 to three. Now, this information is not actually complete because if I tell you that I'm dealing with a hexadecinoic acid, all you're going to know is we have 16 carbon atoms and somewhere in that molecule we have a double bond. What you won't know is where that double bond is actually found. So the question is how do we actually determine or how do we describe the location of that double bond? Well, the way that we begin is we begin by numerically labeling, numbering these carbons.