Zhang Jun and Li Peng are well-known young people who love to play tricks in the community. One day, the two of them wanted to play with Ma Xiaotiao from the takeaway shop again. When it was close to noon, Zhang Jun called Ma Xiaotiao and asked him to bring two boxed lunches, each priced at ten yuan; Jun searched his pockets and found no change, so he took out a piece of 100 yuan and gave it to Ma Xiaotiao. Ma Xiaotiao retrieved 80 yuan and gave it to Zhang Jun. Just as Ma Xiaotiao turned to leave. Li Peng came out of the room suddenly and shouted: "Oh! If you don't have any change, don't tell me earlier. I just have 20 yuan here! Come on, Ma Xiaotiao, I'll give you the 20 yuan, and you return the 100 yuan." Us. Remember, next time I don’t have any change, I will ask Li Peng, haha..." Ma Xiaotiao happily gave them 100 yuan, and then left gratefully. Smart kid, let's do the math, is Ma Xiaotiao winning or losing? How much is the loss or gain?
张军和李朋是小区里有名的爱耍小聪明的青年．一天，他们二人又想和外卖店的马小跳玩一玩．临近中午时，张军就打电话给马小跳，让他送来两份价格都为十元的盒饭；15分钟后，马小跳风尘仆仆地来到张军家，把盒饭给了张军，张军搜遍口袋，发现没有零钱，就拿出一张100元给了马小跳，马小跳找回80元给了张军．正在马小跳转身要走时．李朋突然从房间里走了出来，大声叫着："哎呀！没零钱不早说，我这刚好有20元钱嘛！来，马小跳，这20元给你，你把那100还给我们．记住，下次没零钱找我李朋，哈哈…"马小跳还乐不可支地把100元给了他们，然后满怀感激地离开了．聪明的小朋友，你来算算马小跳到底是赚是赔？赔或赚是多少元？
<gadget id="calculator">20 - 20</gadget>
<output>0</output>

<gadget id="calculator">100 + 0</gadget>
<output>100</output>

<result>100</result>