This letter comes in two versions: addition/subtraction and multiplication/division. The letters explain the importance of fact fluency as part of a complete math curriculum, citing research and providing examples, and gives suggestions for parents to help their child practice math facts at home. A great resource for parents who protest that fact fluency is JUST about memorizing facts! Enjoy!
I also have a letter specifically for the use of Xtramath.org, a website I require students use at home to work towards mastering their facts. Check this out if you use Xtramath in your classroom!