The surface area of a cylinder with a base diameter of 10 cm and a height of 4 decimeters.
底面直径10厘米、高4分米的圆柱表面积．
<gadget id="calculator">4 * 10</gadget>
<output>40</output>

<gadget id="calculator">3.14 * 10 * 40</gadget>
<output>1_256</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

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

<gadget id="calculator">3.14 * 25 * 2</gadget>
<output>157</output>

<gadget id="calculator">1_256 + 157</gadget>
<output>1_413</output>

<result>1_413</result>