The school built a library building, which actually cost 800,000 yuan, which was 200,000 yuan less than the original plan. How much was the savings?
学校建一幢图书楼，实际用了80万，比原计划节约了20万，节约了百分之几？
<gadget id="calculator">20 + 80</gadget>
<output>100</output>

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

<result>1/5 = around 0.2</result>