How many (1/5) of 15 cards are there?
15张卡的(1/5)有多少张．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">15 * (1/5)</gadget>
<output>3</output>

<result>3</result>