Parents go back to school to be able to help kids with math homework

Is anyone keeping an eye on the teachers? My kids realized by fourth or fifth grade that some of their elementary math teachers had very weak math skills and could not keep pace with the more capable students.

A couple of times, they asked my advice on whether or how to correct teachers, or what to do if they were told they were wrong when they gave an “out of the box” method for getting a correct answer.