Find the sum of all the simplest fractions with a denominator of 2 between 3 and 9.
求出3至9之间所有分母为2的最简分数之和．
<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">11 / 2</gadget>
<output>11/2 = around 5.5</output>

<gadget id="calculator">13 / 2</gadget>
<output>13/2 = around 6.5</output>

<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">17 / 2</gadget>
<output>17/2 = around 8.5</output>

<gadget id="calculator">(7/2) + (9/2) + (11/2) + (13/2) + (15/2) + (17/2)</gadget>
<output>36</output>

<result>36</result>