Cut a rectangle 20 decimeters long and 12 decimeters wide into squares of the same size, leaving no paper left. At least how many squares can be cut?
把一张长20分米，宽12分米的长方形裁成同样大小的正方形，纸没有剩余．至少可以裁多少个正方形？
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

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

<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<result>15</result>