Mr. Wang has finished running the blackboard newspaper (5/7), how much is left unfinished?
王老师办黑板报，已经办完了(5/7)，还剩下几分之几没有完成？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

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