workers process 1200 parts in 5 days. According to this calculation, how many parts can be processed in the same number of days by adding 9 workers?
3个工人5天加工零件1200个．照这样计算，增加9个工人，同样的天数可以加工多少个零件？
<gadget id="calculator">1_200 / 3</gadget>
<output>400</output>

<gadget id="calculator">3 + 9</gadget>
<output>12</output>

<gadget id="calculator">400 * 12</gadget>
<output>4_800</output>

<result>4_800</result>