If what you want to do is to obtain a textual representation of the value, with two decimal places, DecimalFormat is indeed the way to go.
If what you want to do is to perform calculations using only two decimal places, then you should not be using floating-point arithmetic. Instead, you should do integer calculations, using "hundredths" (if you're doing currency, call them "cents", "pence" etc.).
Betty Rubble? Well, I would go with Betty... but I'd be thinking of Wilma.