The school playground is a rectangle with a length of 0.6 km and a width of 0.42 km. Xiaofang ran two and a half laps along the playground. How many kilometers did Xiaofang run in total?
学校操场是一个长方形，长0.6千米，宽0.42千米．小芳沿着操场跑了两圈半，小芳一共跑了多少千米？
<gadget id="calculator">0.6 + 0.42</gadget>
<output>1.02</output>

<gadget id="calculator">1.02 * 2 * 2.5</gadget>
<output>5.1</output>

<result>5.1</result>