First, the length of the cylindrical steel pipe is 5m, the outer diameter is 12cm, the inner diameter is 8cm, and the steel weight is 7.8g per cubic centimeter. How many kilograms does the steel pipe weigh?
一要圆柱形钢管长5m，外直径12cm，内直径8cm，每立方厘米钢重7.8g，这要钢管重多少千克？
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

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

<gadget id="calculator">36 - 16</gadget>
<output>20</output>

<gadget id="calculator">7.8 / 1_000</gadget>
<output>0.0078</output>

<gadget id="calculator">3.14 * 20 * 5 * 100 * 0.0078</gadget>
<output>244.92</output>

<result>244.92</result>