Read a technical book, you can read it in 3 days (3/20), how many days will it take to finish reading this book.
读一本科技书，3天可读它的(3/20)，读完这本书共需多少天．
<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">3 / (3/20)</gadget>
<output>20</output>

<result>20</result>