I have never been in this boat before as a parent. However,once upon a time I was a young 4-year-old first grader in class with 6 and 1/2 to 7 year-old children. I highly suspect the issue has nothing to do with math achievement although the librarian and the teacher are likely skeptical of your claims as well.
I suspect the real issue has to do with the perceived maturity of your 4-year-old as well as your required presence. I seriously doubt that the parents of the 2nd to 4th graders will be sitting with their children as they have been in schools for years. Perhaps this teacher would feel more comfortable without a parent hanging around and/or thinks the children will be more focused without a parent hanging around.
Perhaps you can let them know that your child is mature enough not to need you to hang around. Although that may not work either if they don't want to be responsible for such a young child.

Last edited by Quantum2003; 05/16/14 09:38 AM.