A rectangle is 16cm wide and 20% shorter than its length, what is its area in cm**2.
一个长方形，宽16cm，比长短20%，面积是多少cm**2．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">16 / (4/5)</gadget>
<output>20</output>

<gadget id="calculator">20 * 16</gadget>
<output>320</output>

<result>320</result>