Don't Panic! When our children bring home grades that are disappointing to us we may express our disappointment in a way that create tensionn between you and your child. So, try to remain calm and discuss the issue when you've had time to process the situation.
Develop a Plan! Implement positive reinforcement to motivate your child to work harder at achieve good grades. Be supportive of your child and encourage them to work to their full potential.
Have a conversation with your child! Discuss what went wrong. Sit down and have a serious talk with your child to find what they're challenges were and what could be done to help them to correct the matter.
Take an Active Role! As the parent you may need to implement some restrictions to send a message to you child (no tv, cell phone usage, internet, etc) and to establish some boundaries with your child to ensure that they are using their time more effectively and eliminate the distractions that may be causing them to have poor grades.
Communicate with your Child's Teachers! Always remember that you and your chld's teacher are a team and that positive and consisitent communication are key to your child's academic success.
Most of all be patient you may not see the results right away, but if your child remains consistent in working towards achieving better grades they will eventially reap the rewards!