The current price of a pen is 12 yuan, which is 80% of the original price. How much is the original price?
一支钢笔现价12元，现价是原价的80%，原价是多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">12 / (4/5)</gadget>
<output>15</output>

<result>15</result>