The master and the apprentice cooperate to produce a batch of parts. The master produces 40 per hour, and the apprentice produces 30 per hour. When the task is completed, the apprentice produces exactly 450. How many parts are there in total?
师徒两人合作生产一批零件，师傅每小时生产40个，徒弟每小时生产30个，完成任务时徒弟正好生产了450个，这批零件共多少个？
<gadget id="calculator">450 / 30</gadget>
<output>15</output>

<gadget id="calculator">40 * 15</gadget>
<output>600</output>

<gadget id="calculator">600 + 450</gadget>
<output>1_050</output>

<result>1_050</result>