The earth's orbit around the sun is approximately a circle, and the radius of this circle is about 150 million kilometers. How many billions of kilometers does the earth travel around the sun?
地球绕太阳运行的轨道近似一个圆形，这个圆的半径约为1.5亿千米，地球绕太阳一周的行程为多少亿千米？
<gadget id="calculator">2 * 3.14 * 1.5</gadget>
<output>9.42</output>

<result>9.42</result>