There is a postcard that is 12cm long and 9cm wide. Spread such postcards on the table to form a square, at least how many postcards are enough?
有一种明信片长12cm，宽9cm．将这样的明信片平铺在桌子上，想要拼成一个正方形，请问至少要多少张才够？
<gadget id="calculator">9 / 12</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 * 2 * (3/4)</gadget>
<output>3</output>

<gadget id="calculator">9 / 9</gadget>
<output>1</output>

<gadget id="calculator">2 * 2 * 1</gadget>
<output>4</output>

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

<result>12</result>