A cylindrical cup with a bottom radius of 10 cm is filled with water at a height of 7 cm. A small piece of iron is immersed in the water. At this time, the water rises to 9 cm. What is the volume of this piece of iron?
在底面半径是10厘米的圆柱形杯中，装有7厘米高的水，把一小块铁浸入水中，这时水上升到9厘米，问这块铁的体积多大？
<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">9 - 7</gadget>
<output>2</output>

<gadget id="calculator">3.14 * 100 * 2</gadget>
<output>628</output>

<result>628</result>