Processing a batch of parts was originally planned to be completed in 15 days, but actually processed 30 more per day. As a result, the task was completed in only 10 days. How many parts are there in this batch?
加工一批零件，原计划15天完成，实际每天多加工30个，结果只用10天就完成任务，这批零件有多少个？
<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<gadget id="calculator">10 / 5</gadget>
<output>2</output>

<gadget id="calculator">30 * 2 * 15</gadget>
<output>900</output>

<result>900</result>