How do you work a scientific calculator for fractions?

On most calculators you will have a button with that looks like a fillied in rectangle on top of a line on top of an empty rectangle. This button is commonly in on the top lot of buttons on the calcultor.

You just press then number you want at the top of the fraction (numerator), then the button described above, then press the number you want at the bottom of the fraction (denominator). et voila.