If the radius of a circle is 1 cm, what is the circumference of its semicircle in cm?
一个圆的半径1cm，它的半圆周长是多少cm．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 * 3.14 * (1/2)</gadget>
<output>3.14</output>

<gadget id="calculator">2 * 1</gadget>
<output>2</output>

<gadget id="calculator">3.14 + 2</gadget>
<output>5.14</output>

<result>5.14</result>