In a parking lot, there are 12 four-wheeled cars and two-wheeled motorcycles, with a total of 38 wheels. How many four-wheeled cars are there in the parking lot?
一个停车场，停有四轮轿车和两轮摩托车12辆，共有轮子38个．停车场中四轮轿车有多少辆．
<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<gadget id="calculator">38 - 24</gadget>
<output>14</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">14 / 2</gadget>
<output>7</output>

<result>7</result>