chemical fertilizer factory completed (2/3) of the annual plan in the first half of last year, and completed (7/10) of the annual plan in the second half of last year. By what percentage did the fertilizer factory overfulfill the annual plan last year?
某化肥工厂去年上半年完成全年计划的(2/3)，下半年完成全年计划的(7/10)，该化肥厂去年超额完成了全年计划的几分之几？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(7/10) - 1</gadget>
<output>-3/10 = around -0.3</output>

<gadget id="calculator">(2/3) + (-3/10)</gadget>
<output>11/30 = around 0.366667</output>

<result>11/30 = around 0.366667</result>