If a rectangular cardboard with a length of 30 cm and a width of 20 cm is assembled into a smallest square, how many pieces of such cardboard are needed?
把一种长30厘米，宽20厘米的长方形硬纸板，拼成一个最小的正方形，需要多少块这样的硬纸板？
<gadget id="calculator">2 * 2 * 3 * 5</gadget>
<output>60</output>

<gadget id="calculator">60 / 30</gadget>
<output>2</output>

<gadget id="calculator">60 / 20</gadget>
<output>3</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>