给定一段英文文本，使用合适的语言和风格将其重述为一段给孩子们听的故事。
John had a difficult time at school today. He didn't understand the math lesson and his classmates made fun of him. When he got home, he cried to his mom about it.
Once upon a time, there was a boy named John who had a tough day at school. In math class, he struggled to understand the lesson, and to make things worse, his classmates teased him. When John got home, he couldn't hold his tears back and he cried to his mom about what had happened.