A piece of round steel with the same height as the bucket and a radius of 5 cm at the bottom is placed in a cylindrical bucket. If it is put into the water vertically, the water level in the bucket will rise by 9cm. If the round steel in the water is exposed by 8cm, then the water level in the bucket will drop by 4cm. Find the volume of this section of round steel.
在一个圆柱形水桶里放一段与桶同高且底面半径是5cm的圆钢．如果把它全部垂直放入水中，桶内的水面就上升9cm，如果把水中的圆钢露出8cm，那么这时桶里的水面下降4cm，求这段圆钢的体积．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">78.5 * (4/9)</gadget>
<output>34.888889</output>

<gadget id="calculator">200 / 34.888889</gadget>
<output>5.732484</output>

<gadget id="calculator">3.14 * 5.732484</gadget>
<output>18</output>

<gadget id="calculator">3.14 * 25 * 18</gadget>
<output>1_413</output>

<result>1_413</result>