A book has 90 pages, if you read (1/10) of it every day, how many days can you finish it.
一本书有90页，每天看它的(1/10)，多少天可以看完．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / (1/10)</gadget>
<output>10</output>

<result>10</result>