Fill in the numbers according to the law: (1/2), (3/5), (8/13), (21/34), how many.
按规律填数：(1/2)，(3/5)，(8/13)，(21/34)，多少．
<gadget id="calculator">21 + 34</gadget>
<output>55</output>

<gadget id="calculator">55 + 34</gadget>
<output>89</output>

<gadget id="calculator">55 / 89</gadget>
<output>55/89 = around 0.617978</output>

<result>55/89 = around 0.617978</result>