A workshop processes a batch of parts, completes (3/5) of the plan for the first half of the year in the first quarter, and (5/8) of the plan for the first half of the year in the second quarter, resulting in an overproduction of 450 parts. How many parts are planned to be processed in the first half of the year?
一个车间加工一批零件，第一季度完成上半年计划的(3/5)，第二季度完成上半年计划的(5/8)，结果超产450个零件，计划上半年加工多少个零件？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">(5/8) - 1</gadget>
<output>-3/8 = around -0.375</output>

<gadget id="calculator">(3/5) + (-3/8)</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">450 / (9/40)</gadget>
<output>2_000</output>

<result>2_000</result>