There are 18 boys and 18 girls in class 1 of the third grade to participate in the parade and group gymnastics performance. During the parade performance, every 4 people stand in a row. How many rows can they stand?
三年级1班有男生和女生各18人参加队列和团体操表演，队列表演时每4人站一行，能站几行？
<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">18 * (1/2)</gadget>
<output>9</output>

<result>9</result>