If you park a car at the gate of the playground, you need to pay 3 yuan for the first hour, and 2 yuan for every hour thereafter. The owner of a car paid 13 yuan for how many hours he parked.
在游乐场门口停小汽车，第一小时需付款3元，以后每小时付款2元．一辆小汽车主人付了13元，他停了多少小时．
<gadget id="calculator">13 - 3</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

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

<result>6</result>