Good job on beating your mom! (Some of the folks not in the United States might not "get it" since they don't know the "old" pennies have a different back.)
DMC. Good idea, but I find the shadows from only one light source annoying and better DOF throughout the entire range would have made it more striking and harder to find the penny.
Nice tie to the challenge, and that bumps it to a 6 among a lot of photos that didn't try as hard. The composition is not that interesting to me and the lighting seems a bit harsh with reflections and hot spots, or this would have scored higher. 6