Find the rules and fill in: (11/13), (9/11), how much, (5/7), (3/5), (1/3).
找规律填一填：(11/13)、(9/11)、多少、(5/7)、(3/5)、(1/3)．
<gadget id="calculator">9 - 2</gadget>
<output>7</output>

<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<result>7/9 = around 0.777778</result>