The fruit shop sells 100 baskets of fruit a day, and 42 boxes of fruit in the morning, 50 kilograms per basket. According to this calculation, how many kilograms more will the fruit shop sell in the afternoon than in the morning?
水果店一天卖出100筐水果，上午卖出42箱，每筐50千克，照这样计算，水果店下午比上午多卖出多少千克？
<gadget id="calculator">42 * 2</gadget>
<output>84</output>

<gadget id="calculator">100 - 84</gadget>
<output>16</output>

<gadget id="calculator">16 * 50</gadget>
<output>800</output>

<result>800</result>