The engineering team completes a project, completing (2/7) of it on the first day, (1/2) of it on the second day, and the rest on the third day. What fraction of it was completed on the third day?
工程队完成一项工程，第一天完成了它的(2/7)，第二天完成了它的(1/2)，其余的第三天完成．第三天完成了它的几分之几？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (2/7) - (1/2)</gadget>
<output>3/14 = around 0.214286</output>

<result>3/14 = around 0.214286</result>