hollow cylindrical steel pipe is 1 meter long, the outer diameter is 10 cm, and the inner diameter is 6 cm. If the steel pipe weighs 7.8 grams per cubic centimeter, how much does the steel pipe weigh in grams?
一根空心圆柱钢管，长1米，外圆直径是10cm，内圆直径6cm，如果每立方厘米钢管重7.8克，那么这根钢管重多少克？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

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

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">25 - 9</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16 * 1 * 100 * 7.8</gadget>
<output>39_187.2</output>

<result>39_187.2</result>