The parent chain and the numbers are marked as red in the image.
Work Step by Step
1. Find the parent chain. In this case, the rules are: - It has to contain the ketone. - It has to be as large as possible (9 carbons). 2. Identify where you are supposed to start counting. The counting should start from the left, since there is a double bond next to it. ** We need to count in a way that, the double bond will get the minimum number possible, which we do by starting from the top.