The engineering team planned to dig an 800-meter canal in 20 days, but actually completed the task in 16 days. By what percentage has the actual work efficiency of the engineering team improved compared to the plan?
工程队计划20天挖一条800米的水渠，实际16天就完成了任务．工程队的实际工作效率比计划提高了百分之几？
<gadget id="calculator">800 / 16</gadget>
<output>50</output>

<gadget id="calculator">800 / 20</gadget>
<output>40</output>

<gadget id="calculator">50 - 40</gadget>
<output>10</output>

<gadget id="calculator">10 / 40</gadget>
<output>1/4 = around 0.25</output>

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