Xiaoming's family used up a bottle of oil in 4 days (1/4), so how many days can this bottle of oil last?
小明家4天用去一瓶油的(1/4)，照这样，这瓶油能用多少天．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) / 4</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">1 / (1/16)</gadget>
<output>16</output>

<result>16</result>