For a piece of work, what has been completed this month is unfinished (3/5), so what is unfinished is the total workload of this month.
一件工作，本月份已经完成的是未完成的(3/5)，那么未完成的是本月总工作量的多少．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 + (3/5)</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">1 / (8/5)</gadget>
<output>5/8 = around 0.625</output>

<result>5/8 = around 0.625</result>