The fifth-grade students walked to the spring outing. They walked 3.45 kilometers in the first hour and 4.55 kilometers in the second hour. The distance traveled in two hours is exactly half of the whole journey. How many kilometers is the whole journey?
五年级学生步行去春游，第一小时行了3.45千米，第二小时行了4.55千米，两小时行的路程恰好是全程的一半，全程是多少千米？
<gadget id="calculator">3.45 + 4.55</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<result>16</result>