Don't forget that your efforts with your child's learning are as valuable as the efforts of their teachers. You can have a huge effect on your child's learning at home, by encouraging them to try hard and do well in their studies. There are a number of things you can do at home to enhance your child's mathematical skills if they appear to be struggling with their math studies at school.
If you find that your child is still really struggling after a number of efforts at home, there is one final thing you can do. The option of hiring a personal tutor is becoming more popular throughout the States. Personal tutors can help your child get to grips with things they never used to understand and provide a more personal form of education. The personal tutor will become more of a friend to your child, than a teacher, meaning the teaching style will be vastly different to that of their school. It's one of the best ways of helping a struggling child.