In a car parking lot, you have to pay at least 0.5 yuan once. If you park for more than 1 hour, you will have to pay an additional 0.5 yuan for every 0.5 hours you park. The car paid 5.5 yuan when it left the parking lot. How many hours has the car been parked?
在一个汽车停车场一次至少要交费0.5元．如果停车超过1小时，每多停0.5小时就要多交0.5元．这辆汽车在离开停车场时交了5.5元．这辆汽车停了多少小时．
<gadget id="calculator">5.5 - 0.5</gadget>
<output>5</output>

<gadget id="calculator">0.5 + 0.5</gadget>
<output>1</output>

<gadget id="calculator">5 / 1</gadget>
<output>5</output>

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<result>6</result>