A rectangular iron plate with a length of 28 decimeters and a width of 21 decimeters can be cut into a circular iron plate with a radius of 35 centimeters.
一张长28分米、宽21分米的长方形铁板，最大能剪成半径是35厘米的圆形铁板多少块．
<gadget id="calculator">3.5 * 2</gadget>
<output>7</output>

<gadget id="calculator">28 / 7</gadget>
<output>4</output>

<gadget id="calculator">21 / 7</gadget>
<output>3</output>

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

<result>12</result>