Can you get change for a penny in the United States?

Born Texan but im sure we all ( Americans ) have seen the gas pump and the price which is locally $2.49 9/10. Which is my point why or what is the reason behind the 9/10th's? Its not like if you pump just the right amount and paid cash before pumping you will ever get 9/10th of a penny back so what's the 9/10 after $2.49 a gallon all about or the logic behind it? Why not just say $2.50?