Great question h22!
First up, this depends on the platform you're developing /designing the app for.
If it's Tizen, the new Samsung Gear 2 is designed for a round smartwatch. So, developing for Tizen will allow you to do that. You can see that in the Design Documentation for Tizen, it is catered towards the round watch face and proudly showcases the usages of the bezel as well. As you can see in the screenshot, Tizen isn't afraid to use the circular space of the watch and make the list easily scrollable, but display one item at a time.
Android, on the other hand, advises you to be wary of the square watch face as well. You should design for the Square watch face on Android and it'll automatically handle the complexities to adjust it on the round smartwatch. The Design documentation for Android Wear heavily showcases the Square watch face. A list on Android Wear consists of 3 list items on the screen out of which the one in the center is focused on. It offers a very minimal and spacious alternative to Tizen.
So, depending on your wristful decision of choosing the Wearable OS, Tizen will allow you to rotate the numbers and get away with it, but Android might be a little complicated since restricting Square watch users to your app isn't really the way designers should go about.
Regarding the white space and margins: It is perfectly fine to have large margins on the Wearable. Since the screen size is small, you need information to be loud and concise. Showing a lot of data could get very overwhelming and hard to read.
So to answer your question, Yes, you can guide the user using rotating numbers on a Samsung Tizen smartwatch i.e. Gear 2. You should read more information on the circular design here.