Coins

Australia coins come in different denominations than American coins - 5, 10, 20, and 50 cents, plus 1 and 2 dollars. What's weird is that they don't really seem to have names for them, like in America. No penny, nickel, dime, quarter... or anything like that. You don't really even ever hear "five cent piece", "ten cent piece", etc. that much. They just don't seem to require names, and are hardly ever mentioned. I wonder why?