The charging standard of a parking lot is: 2 yuan within 5 hours, 0.8 yuan per hour for more than 5 hours. Dad parks in this parking lot for 7 hours, how much should he pay?
一停车场的收费标准是：5小时以内收费2元，超过5小时的，每小时0.8元．爸爸在这个停车场停车7小时，他应交费多少元．
<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">2 * 0.8</gadget>
<output>1.6</output>

<gadget id="calculator">1.6 + 2</gadget>
<output>3.6</output>

<result>3.6</result>