Wanfeng Group produced a batch of auto parts, and produced 1,200 boxes in the first 8 days. According to this calculation, the remaining ones were completed in just 4 days. How many boxes are there in this batch of parts? (Solve with ratio)
万丰集团生产一批汽车零件，前8天生产了1200箱，照这样计算，剩下的刚好4天完成．这批零件共有多少箱？(用比例解)
<gadget id="calculator">1_200 / 8</gadget>
<output>150</output>

<gadget id="calculator">150 * 8</gadget>
<output>1_200</output>

<gadget id="calculator">150 * 4</gadget>
<output>600</output>

<gadget id="calculator">1_200 + 600</gadget>
<output>1_800</output>

<result>1_800</result>