There were originally 16 cars in the parking lot, but after some of them were driven away, there were still (3/4) left. How many cars were driven away?
停车场原有16辆轿车，开走一些后还剩下(3/4)，开走了多少辆？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">16 * (3/4)</gadget>
<output>12</output>

<gadget id="calculator">16 - 12</gadget>
<output>4</output>

<result>4</result>