A steel pipe has an inner diameter of 8 cm, a wall thickness of 1 cm, and a length of 1 m. What is the volume of this pipe in cubic centimeters?
一根钢管，内直径8厘米，管壁厚1厘米，长1米．这根钢管的体积有多少立方厘米？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<gadget id="calculator">78.5 - 50.24</gadget>
<output>28.26</output>

<gadget id="calculator">28.26 * 1 * 100</gadget>
<output>2_826</output>

<result>2_826</result>