A machine tool factory completed the monthly plan (3/5) in the first half of April, and completed the monthly plan (5/6) in the second half of April. What percentage of the monthly plan was overfulfilled this month?
某机床厂4月份上半个月完成月计划的(3/5)，下半月完成月计划的(5/6)，这个月超额完成月计划任务的几分之几？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(5/6) - 1</gadget>
<output>-1/6 = around -0.166667</output>

<gadget id="calculator">(3/5) + (-1/6)</gadget>
<output>13/30 = around 0.433333</output>

<result>13/30 = around 0.433333</result>