On a plan with a scale of 1:2200000, the distance from Kunming to Liujie on the map is 3.5 centimeters. What is the actual distance in kilometers?
在比例尺是1﹕2200000的平面图上，量得昆明到六街的图上距离是3.5厘米，实际距离是多少千米．
<gadget id="calculator">1 / 2_200_000</gadget>
<output>1/2_200_000 = around 0</output>

<gadget id="calculator">3.5 / (1/2_200_000) / 100_000</gadget>
<output>77</output>

<result>77</result>