I though that but then I saw a chunk of silver beside the rim that could not have been sanded. It wouldn't look like that.
It's not silver, it's steel. The inside is steel with a little bit of nickel, and then it is plated in copper. You'll notice that it'll stick to a magnet. Go spend it, it's just seen some heavy circulation.
Canada has minted both bronze and copper plated steel pennies (cents) for many years. Originally the plated steel had a letter "P" to denote them. It was later dropped and now the best way to tell the difference is using a magnet.