Now there is a task, (2/7) of the task is completed in the first month, and (3/7) of the task is completed in the second month, how many tasks are left to be completed?
现在有一项任务，第一个月完成了任务的(2/7)，第二个月完成了任务的(3/7)，还剩下任务的多少没完成？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (2/7) - (3/7)</gadget>
<output>2/7 = around 0.285714</output>

<result>2/7 = around 0.285714</result>