Dad reads a book (1/5) every day, how many days can he finish it.
爸爸每天看一本书的(1/5)，多少天可以看完．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / (1/5)</gadget>
<output>5</output>

<result>5</result>