When the moon revolves around the earth, its orbit can be approximated as a circle. The measured orbital radius is about 384,400 kilometers. How many kilometers is it around the earth?
月球绕地球旋转时，它的轨道可近似地看作圆，测得轨道半径约384400千米，它绕地球一周约是多少千米？
<gadget id="calculator">2 * 3.14 * 384_400</gadget>
<output>2_414_032</output>

<result>2_414_032</result>