3.14*(1/5)+3.14*(4/5).
3.14*(1/5)+3.14*(4/5)．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3.14 * (1/5)</gadget>
<output>0.628</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3.14 * (4/5)</gadget>
<output>2.512</output>

<gadget id="calculator">0.628 + 2.512</gadget>
<output>3.14</output>

<result>3.14</result>