The expansion of the teaching building of Guangming Primary School originally planned to invest 200,000 yuan, but the actual investment was 180,000 yuan. How much was the actual savings compared to the plan?
光明小学扩建教学楼，原计划投资20万元，实际投入18万元，实际比计划节约了百分之几？
<gadget id="calculator">20 - 18</gadget>
<output>2</output>

<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

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