There are 3 plastic pipes with a cross-section of 12.56, tie them into a bundle with a rope, find the outer circumference.
有3根横截面为12.56的塑料管，用绳子把它们扎紧成一捆，求外周长．
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>