If you are not familiar with this resource, you should check it out. Totally free. Gets the parent out of the picture when it comes to helping with homework. Whats great is that videos illustrate principals quickly with SHORT videos. No long winded lectures. Just right to the point with short illustrations. You just see the "black board." No teacher yapping away. Every parent I know who has checked it out has great things to say about it. NO ADS at all. None. You won't get any spam if you visit the site. The kids I know of all ages also have good things to say. This is great for kids of almost any age.

https://www.khanacademy.org/