The original plan to invest 4 million yuan in building a new bridge actually saved 7.5% compared to the plan. How much yuan was saved?
新建一座大桥，原计划投资400万元，实际比计划节约了7.5%，节约了多少万元？
<gadget id="calculator">7.5 / 100</gadget>
<output>0.075</output>

<gadget id="calculator">400 * 0.075</gadget>
<output>30</output>

<result>30</result>