CK-12 (Learning and Teaching Tool)
You can use these great resources at home to help your child perform better in school. When your child asks you for help with his/her assignment and it has been years since you learned the concept, simply log on to the site (www.ck12.org) and search for material in multiple modalities. You can learn and re-learn the concept together! It’s also great for reinforcing lessons and going beyond the learning we have time for in class.
What’s best is that all the materials are completely free to everyone, all the time.