The time it takes for Master Wang to assemble a machine has been shortened by 20% compared to the past, how much his work efficiency has improved compared to before.
王师傅装配一台机器所用的时间比过去缩短了20%，他的工作效率比以前提高了多少．
<gadget id="calculator">1 / 1</gadget>
<output>1</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 * (4/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 1 / (4/5)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(5/4) - 1</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) / 1 / 1</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(1/4) * 1</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>