Use rectangular paper with a length of 12cm and a width of 9cm to make a square, how many rectangles should be used?
用长12cm、宽9cm长方形纸拼正方形，要用多少个长方形．
<gadget id="calculator">36 / 12</gadget>
<output>3</output>

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

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

<result>12</result>