Welcome! Your coin is worth 10 cents. Someone ground down the obverse. It didn't come from the mint like that.
First, welcome to the neighborhood, Robert! We see these, from all denominations (!) all the time. Some people have nothing better to do while others are just trying to cheat people out of their money.
You'd be surprised how often people come here to ask if this type of damage is a real Mint Error, and many times it is after they already bought it.
That's one of the best grounded down job I've seen on a coin like that.Keep it as a good magic trick coin surprise the kids.
It was ground off by someone that was very bored. It’s still worth ten cents. Not an error. Welcome to CT.