The original price of a product is 80 yuan, and it rises to 100 yuan during the National Day. How much is the increase? What is the correct column
一件商品的原价是80元，国庆期间上涨到100元，上涨了百分之几？正确列式是多少
<gadget id="calculator">100 - 80</gadget>
<output>20</output>

<gadget id="calculator">20 / 80</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>