The current price of a coat is 100 yuan, which is (1/5) lower than the original price. How much is the original price?
一件上衣现价100元，比原价降低了(1/5)，原价多少元．
<gadget id="calculator">1 / 5</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">100 / (4/5)</gadget>
<output>125</output>

<result>125</result>