I'm not sure it's fair to force parents to be experts on all subjects. If a child's parents don't speak English very well and have never learned geometry, how are they supposed to check over a child's geometry homework? The teacher should have the responsibility of providing the child with good course material, whether it's the book or supplemental material, plus notes from their class. The students should have everything they need in their hands. Not all kids have access to the internet easily. Some are on shared computers at home, with time limits, if they even do have a full internet connection at home.