Unfortunately, many schools today have inflated the grades in order to pass students from grade to grade. Your child's A's may indeed have not been A's and this could be a reason for her struggling. It could also be due to poor teaching. I would look for an older student, former teacher or someone who could tutor her. It is worth the money to get her help now before she goes on to college or into the workforce. Inadequate instruction in math is a nationwide problem because children don't master arithmetic before being thrown into algebra, geometry or calculus. Talk to other parents as well. You may be very surprised at their responses.