The expansion of the teaching building of Wangdong Primary School originally planned to invest 400,000 yuan, but actually used 360,000 yuan. What percentage was the actual saving compared to the plan?
王东小学扩建教学楼，原计划投资40万元，实际用了36万元，实际比计划节约了百分之几？
<gadget id="calculator">40 - 36</gadget>
<output>4</output>

<gadget id="calculator">4 / 40</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>