Vegetables in the supermarket can get a 20% discount with the discount card. Aunt Li bought some celery with the discount card and saved 2.4 yuan. How much is the original price of these celery?
超市的蔬菜凭优惠卡可打八折，李阿姨用优惠卡买了一些芹菜，省了2.4元．这些芹菜的原价是多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2.4 / (1/5)</gadget>
<output>12</output>

<result>12</result>