If the length of a rectangle is increased by (1/5), how much should its width be reduced to keep its area constant?
把一个长方形的长增加(1/5)，要使它的面积不变，它的宽应该减少多少
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>