The cement plant planned to produce 120,000 tons of cement in March. In fact, it produced 69,000 tons in the first half of the month and 81,000 tons in the second half of the month. How much was exceeded in March?
水泥厂3月份计划生产水泥12万吨，实际上半月生产6.9万吨，下半月生产8.1万吨，3月份超额完成计划的多少．
<gadget id="calculator">8.1 - 12</gadget>
<output>-3.9</output>

<gadget id="calculator">6.9 + (-3.9)</gadget>
<output>3</output>

<gadget id="calculator">3 / 12</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>