Processing a batch of parts, if processing 150 parts per day, it will be completed 1 day earlier than planned, if processing 100 parts per day, it will be completed one day later than planned, if it is required to complete according to plan, how many parts should be processed per day?
加工一批零件，如果每天加工150个，比计划提前1天完成，如果每天加工100个，比计划拖延一天完成，如果要求按计划完成，每天应该加工多少个？
<gadget id="calculator">150 + 100</gadget>
<output>250</output>

<gadget id="calculator">150 - 100</gadget>
<output>50</output>

<gadget id="calculator">250 / 50</gadget>
<output>5</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">150 * 4</gadget>
<output>600</output>

<gadget id="calculator">600 / 5</gadget>
<output>120</output>

<result>120</result>