A worker originally planned to produce 120 parts in 15 days. After the reform, 2 parts will be added every day. How many days will it actually take?
一个工人原计划15天生产120个零件，改革后，每天增加2个，实际要多少天？
<gadget id="calculator">120 / 15</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">120 / 10</gadget>
<output>12</output>

<gadget id="calculator">120 / 12</gadget>
<output>10</output>

<result>10</result>