If a fraction is added to one of its fractional units, the result is (5/8), and if one of its fractional units is subtracted, the result is (1/2). What is the original fraction?
一个分数若加上它的一个分数单位，约分后是(5/8)，若减去它的一个分数单位约分后是(1/2)，这个分数原来是多少？
<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(5/8) - (1/2)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/8) / 2</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">(5/8) - (1/16)</gadget>
<output>9/16 = around 0.5625</output>

<result>9/16 = around 0.5625</result>