Draw a circle with a radius of 3 cm inside a rectangle with a length of 30 cm and a width of 12 cm. How many such circles can be drawn at most?
在一张长30厘米，宽12厘米的长方形内画半径是3厘米的圆，这样的圆最多能画多少个．
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<gadget id="calculator">12 / 6</gadget>
<output>2</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<result>10</result>