To build a road, 1,200 meters were built in the first 4 days. At this speed, it can be completed in 16 days. How long is the road in total? (Solve with ratio)
修一条公路，前4天修了1200米，照这样的速度，再修16天就可以修完，这条路共长多少米？(用比例解)
<gadget id="calculator">1_200 / 4</gadget>
<output>300</output>

<gadget id="calculator">300 * 16</gadget>
<output>4_800</output>

<gadget id="calculator">300 * 4</gadget>
<output>1_200</output>

<gadget id="calculator">4_800 + 1_200</gadget>
<output>6_000</output>

<result>6_000</result>