After the Yunnan earthquake in 2012, a new teaching building was built in Yiliang County. The actual cost was 4.5 million yuan, which was 1/10 less than the original plan. How much was the original plan?
2012年云南地震后，彝良县新建了一座教学大楼，实际造价450万元，比原计划节约了(1/10)．原计划造价多少万元？
<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">450 / (9/10)</gadget>
<output>500</output>

<result>500</result>