According to "the second day's trading volume increased by (1/5) compared with the first day", we can know how much the second day's trading volume is on the first day.
根据"第二天的成交量比第一天增加了(1/5)"，可以知第二天的成交量是第一天的多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<result>6/5 = around 1.2</result>