A hollow steel pipe is 2 meters long, has an inner diameter of 8 cm, and an outer diameter of 12 cm. If each cubic centimeter of steel weighs 7.8 grams, how many kilograms does this steel pipe weigh?
一根空心钢管长2米，内直径是8厘米，外直径是12厘米．如果每立方厘米的钢材重7.8克，这根钢管重多少千克？
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

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

<gadget id="calculator">3.14 * 36</gadget>
<output>113.04</output>

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

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

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

<gadget id="calculator">113.04 - 50.24</gadget>
<output>62.8</output>

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

<gadget id="calculator">62.8 * 2 * 100 * 0.0078</gadget>
<output>97.968</output>

<result>97.968</result>