The students go to the station to work voluntarily, and 3 students wipe 12 pieces of glass. According to this calculation, how many pieces of glass can 9 students wipe.
同学们到车站义务劳动，3个同学擦12块玻璃，照这样计算，9个同学可以擦多少块玻璃．
<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">4 * 9</gadget>
<output>36</output>

<result>36</result>