Master Wang processes a batch of parts. If he processes 250 parts per day, it will be 2 days later than the original plan; if he processes 300 parts per day on average, he will finish exactly as scheduled. Find the total number of parts in this batch?
王师傅加工一批零件，若每天加工250个，则比原定计划迟2天；若平均每天加工300个零件，正好按原定时间完成．求这批零件的总个数？
<gadget id="calculator">250 * 2</gadget>
<output>500</output>

<gadget id="calculator">300 - 250</gadget>
<output>50</output>

<gadget id="calculator">500 / 50</gadget>
<output>10</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">250 * 12</gadget>
<output>3_000</output>

<result>3_000</result>