A bucket of rapeseed oil contains 5 liters. (1/5) liter is used up, how many liters are left.
一桶菜籽油有5升．用去了(1/5)升，还剩多少升．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 - (1/5)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>