The school built a comprehensive building, with an actual investment of 2.2 million yuan and a saving of 300,000 yuan. How much was the savings?
学校建综合楼，实际投资220万元，节约了30万元，节约了百分之几？
<gadget id="calculator">220 + 30</gadget>
<output>250</output>

<gadget id="calculator">30 / 250</gadget>
<output>3/25 = around 0.12</output>

<result>3/25 = around 0.12</result>