Find the pattern and fill in the blanks: 1, (2/3), (5/8), (13/21), how much.
找规律填空：1，(2/3)，(5/8)，(13/21)，多少．
<gadget id="calculator">13 + 21</gadget>
<output>34</output>

<gadget id="calculator">34 + 21</gadget>
<output>55</output>

<gadget id="calculator">34 / 55</gadget>
<output>34/55 = around 0.618182</output>

<result>34/55 = around 0.618182</result>