To build a building, the actual investment is 36 million yuan, which is (1/10) less than the planned investment. How much do you plan to invest?
建一座大楼，实际投资3600万元，比计划投资节约了(1/10)．计划投资多少万元？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">3_600 / (9/10)</gadget>
<output>4_000</output>

<result>4_000</result>