+5478 Simplest answer: Use parentheses.
Ex: one-third minus two-fifths would be (1/3) - (2/5) = (-1/15),
And one-third times two-fifths would be (1/3) * (2/5) = (2/15).
You could also change the input on the site calculator to "Fractions" by clicking on the gray word "Scientific" (in the answer box) and selecting "Fractions" from the drop-down menu.
