There are (9/10) tons of coal, and how many times it takes to transport (1/10) of it away each time.
有(9/10)吨煤，每次运走它的(1/10)，多少次才能运完．
<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>