To build a sewage treatment plant, the actual investment is planned (9/10), saving 18,000 yuan compared to the plan. How much do you plan to invest?
建造一座污水处理厂，实际投资是计划的(9/10)，比计划节约1.8万元．计划投资多少万元？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1.8 / (1/10)</gadget>
<output>18</output>

<result>18</result>