what is the fraction button on a calculator

(1/3) * pi * 5 * 5 * 9

=  (1/3) * pi * 25 * 9

=  (1/3) * pi * 225

=   (225/3) * pi

=  75 pi          ≈  235.619

To do a fraction on this calculator, you can type it in like this:

numerator / denominator

So, to do:  \(\frac35\)

Type:        3/5

And make sure it displays correctly in the top, otherwise you might need to put parenthesees.