A store sells 20 cartons of milk in the morning and 30 cartons in the afternoon. How much more milk is sold in the afternoon than in the morning?
某商店上午卖出牛奶20箱，下午卖出30箱，下午卖出的牛奶比上午多百分之几？
<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<gadget id="calculator">10 / 20</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>