It took only 8 days to complete a task that was originally planned to take 12 days. How much has the work efficiency improved?
完成一项任务，原计划用12天，实际只用了8天，工作效率提高了多少
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/8) - (1/12)</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">(1/24) / (1/12)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>