A workshop needs to produce 1,800 parts, and it is planned to be completed in 15 days. Due to the improvement of technology, 30 more parts are actually produced every day. How many days did it actually take?
某车间要生产1800个零件，计划15天完成，由于改进技术，实际每天多生产30个零件，实际用了多少天？
<gadget id="calculator">1_800 / 15</gadget>
<output>120</output>

<gadget id="calculator">120 + 30</gadget>
<output>150</output>

<gadget id="calculator">1_800 / 150</gadget>
<output>12</output>

<result>12</result>