文章一开场是"I remember my seventh grade math teacher's name very well. It was Mr Young. He was missing one of his finger."
问题1.怎么理解He was missing one of his finger？

接着就说“我”脑子有点问题，学不好数学。如果再得E就要转学，于是接着下文：
“They shouldn't laugh at you because you can't help you not having a finger,Mr Young.It's just like I can't help not being able to learn numbers and stuff like that."I said
问题2：怎么理解you can't help you not having a finger和I can't help not being able to learn numbers and stuff like that？

最后老师给了他一个D，接着有
That math grade was my favorite one I ever received in my whole life,because I knew that someone in the world finally understood what it was like for me to be missing a finger inside my head
怎么理解what it was like for me to be missing a finger inside my head？

简单回答行了

1、我思考良久，应该就是缺了一根手指吧……至于为什么不加s我也不清楚。
2、can't help的意思是禁不住，无法停止，无法改变。
比如Embrace的歌曲《Gravity》里面
“Cause I can't help crying......”因为我不能停止哭泣。
在这里，这两句话的意思是：你无法改变你失去一根手指，我也无法改变我不能学好数学和诸如此类的麻烦境地。stuff like that是诸如此类的意思。
3、这句话的意思不好表达。直译一下，失去了一根大脑里的指头（指的是我大脑 的缺陷）对我来说是什么样子的。
就是说，终于有人了解并宽容了我数学方面的不足


参考文献：《如何用增大分母的方式降低采纳率》