20 kilograms of gasoline, (3/4) kilograms have been used, how many kilograms are left
20千克汽油，用去了(3/4)千克，还剩多少千克多少
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">20 - (3/4)</gadget>
<output>77/4 = around 19.25</output>

<result>77/4 = around 19.25</result>