Parents need to know that there's nothing but valuable (OK, sometimes not really "valuable" as much as very cool: Do you know why curveballs curve?) information for students of all ages on this well-organized education portal. Most of the links will take kids off the site, but where they land is harmless and educational. Minimal text-only ads are usually related to the topic you've clicked on. It's just unfortunate that they look so much like the other legit content links on the site.
Educational value:Kids will learn something on every part of this site.