St. Ann School is the best catholic school in Delaware. We are going on our 8th year here and could not ask for better faculty, staff and sense of community. The math program changed a few years ago and is very challenging. We love St. Ann School.
This school is great in some ways don't get me wrong i was a student there from kindergarden all the way through but if you want your focus to be in advanced math and things like Geometry are not offered there. The school is very small and may not be what you are looking for. I would pack a lunch. The school is great though, they teachers are so nice and the kids learn even if they don't know it manners and friendship. Even though the class is small you become very close by the end. The only problem is that the disadvantage to it being small is the lack of honors and higher classes, i went into my high school a year behind in math and i will have to take to math classes next year so i can catch up.