A bottle of juice weighs 500 grams. From the label, it can be seen that the net content of this bottle of juice is 480 grams. How many grams does this juice bottle weigh?
一瓶果汁连瓶重500克，从标签可看出这瓶果汁的净含量是480克，这个果汁瓶子重多少克？
<gadget id="calculator">500 - 480</gadget>
<output>20</output>

<result>20</result>