A factory planned to use 400 tons of water last month, but actually saved 17.5%. How many tons did it actually use?
某工厂上月计划用水400吨，实际节约了17.5%，实际用水多少吨？
<gadget id="calculator">17.5 / 100</gadget>
<output>0.175</output>

<gadget id="calculator">1 - 0.175</gadget>
<output>0.825</output>

<gadget id="calculator">400 * 0.825</gadget>
<output>330</output>

<result>330</result>