The actual cost of building a building was 2.4 million yuan, which was 20% less than planned. How much do you plan to spend?
建造一栋楼房，实际用了240万元，比计划节约了20%．计划要用多少万元？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">240 / (4/5)</gadget>
<output>300</output>

<result>300</result>