How many circles with a diameter of 3 cm can be cut out of a rectangular paper with a length of 9 cm and a width of 6 cm.
在一张长9厘米，宽6厘米长方形纸中，最多可以剪多少个直径为3厘米的圆．
<gadget id="calculator">9 / 3</gadget>
<output>3</output>

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

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

<result>6</result>