A cylindrical oil barrel has a bottom circumference of 12.56 decimeters and a height of 8 decimeters. If the surface of the oil barrel is painted with 50 grams of paint per square decimeter, how much paint is needed?
一圆柱形油桶，底面周长12.56分米，高8分米，把油桶的表面刷漆，每平方分米用漆50克，需要多少油漆？
<gadget id="calculator">12.56 * 8</gadget>
<output>100.48</output>

<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">2 * 3.14 * 4</gadget>
<output>25.12</output>

<gadget id="calculator">100.48 + 25.12</gadget>
<output>125.6</output>

<gadget id="calculator">125.6 * 50</gadget>
<output>6_280</output>

<result>6_280</result>