Please help me translate this joke in English, (additional 200)

After the end-of-year examination, xiaoming returned home and told his parents: "Mom, Dad, i scored 100 for two subjecs." After hearing this news, Mom and Dad were overjoyed. Xiaoming added " Both added to 100." After hearing this, Dad was so angry that he raised his fist and was about to beat Xiaoming when mother interrupted, " Even if you scored 40 for Mathematics, you at least score 60 for Chinese, at least one of them past right?" At this moment, xiaojing whispered: " No Mom, that's not how it should be calculated. 10 for Chinese and 0 for Mathematics, added up to 100."

used on the first floor It’s an online translation, with many mistakes. = =ll