bicycle factory planned to produce 12,600 bicycles last year, but completed (1/2) of the plan in the first half of the year and (3/4) of the plan in the second half of the year. How many more bicycles were actually produced than planned?
某自行车厂去年计划生产自行车12600辆，结果上半年完成计划的(1/2)，下半年完成计划的(3/4)，实际比计划多生产了多少辆？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) - 1</gadget>
<output>-1/4 = around -0.25</output>

<gadget id="calculator">(1/2) + (-1/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">12_600 * (1/4)</gadget>
<output>3_150</output>

<result>3_150</result>