Observe the changing law of this series of scores: (1/1), (1/2), (2/2), (1/3), (2/3), (3/3), (1/4), (2/4), (3/4), (4/4), ... then (7/15) is the number.
观察这串分数的变化规律：(1/1)，(1/2)，(2/2)，(1/3)，(2/3)，(3/3)，(1/4)，(2/4)，(3/4)，(4/4)，…则(7/15)是第多少个数．
<gadget id="calculator">1 + 14</gadget>
<output>15</output>

<gadget id="calculator">14 / 2</gadget>
<output>7</output>

<gadget id="calculator">15 * 7</gadget>
<output>105</output>

<gadget id="calculator">105 + 7</gadget>
<output>112</output>

<result>112</result>