It's maddening when you have a 10-year old that has to pay for an adult ticket, is not allowed to order off the kids menu at restaurants, etc.
I've never understood why they don't have an adult price that's for 18+, a Juniors price (or some other name) for 10-17 year old kids, and then a Kids price for 3-9.
Then you could make the adult price more expensive and the kids price cheaper (though I'm not sure that doubling the price for adults is the right way to go about things).