I'm 6. Another kid at school keeps calling me stupid and ugly.

My mom told me to tell him stop it but I don't want to sound mean to him.  I want him to stop.

ANSWER:  In my school and most every classroom there is a sign that's on the wall.  It says:
1. Ignore
2. Say to the person "please stop".
3. Tell the teacher.

If you do that and it doesn’t work try it again.  Say, “STOP!  Now I’m getting very mad. If you keep doing it I’ll get madder and madder.  Then tell the person “I will tell my mom.  I will tell the teacher and I will tell the office at dismissal.”

I’m sorry he hurt your feelings.  I hope this helps you.