A processing factory produced 4500 pieces of products in March 2014, exceeding the original plan (1/8), how many pieces should be produced in the original plan?
某加工厂2014年3月份生产产品4500件，比原计划超产(1/8)，原计划要生产多少件？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 + (1/8)</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">4_500 / (9/8)</gadget>
<output>4_000</output>

<result>4_000</result>