A workshop originally used 150 tons of coal per month. After improving the technology, it uses 127.5 tons of coal per month. How much is the savings?
一个车间，原来每月用煤150吨，改进技术后，每月用煤127.5吨，节约了百分之几？
<gadget id="calculator">150 - 127.5</gadget>
<output>22.5</output>

<gadget id="calculator">22.5 / 150</gadget>
<output>0.15</output>

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

<gadget id="calculator">0.15 * 1</gadget>
<output>0.15</output>

<result>0.15</result>