What is the sum of all the simplest proper fractions whose fraction unit is (1/16).
分数单位为(1/16)的所有最简真分数的和是多少．
<gadget id="calculator">1 / 16</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">3 / 16</gadget>
<output>3/16 = around 0.1875</output>

<gadget id="calculator">5 / 16</gadget>
<output>5/16 = around 0.3125</output>

<gadget id="calculator">7 / 16</gadget>
<output>7/16 = around 0.4375</output>

<gadget id="calculator">9 / 16</gadget>
<output>9/16 = around 0.5625</output>

<gadget id="calculator">11 / 16</gadget>
<output>11/16 = around 0.6875</output>

<gadget id="calculator">13 / 16</gadget>
<output>13/16 = around 0.8125</output>

<gadget id="calculator">15 / 16</gadget>
<output>15/16 = around 0.9375</output>

<gadget id="calculator">(1/16) + (3/16) + (5/16) + (7/16) + (9/16) + (11/16) + (13/16) + (15/16)</gadget>
<output>4</output>

<result>4</result>