The current price of an electric fan is 280 yuan, which is 30% cheaper than the original price. How much is the original price?
一台电风扇现价280元，比原价便宜30%，原价多少元？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">280 / (7/10)</gadget>
<output>400</output>

<result>400</result>