The school invested 1.8 million yuan in building a teaching building, which is 10% less than planned. How much is the planned investment?
学校建一座教学楼投资180万元，比计划节省了10%，计划投资多少万元？
<gadget id="calculator">10 / 100</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">180 / (9/10)</gadget>
<output>200</output>

<result>200</result>