The reason that I mention this is that we see the same problem when homework comes around. I've already talked about how she and John cannot understand that Mike needs a certain level of background noise in order to be able to keep his mind on what he's doing. This lack of awareness of who Mike is and that their advice is worthless because of said ignorance is only half of the problem. The real problem is that they insist on 'helping' him in other useless ways. John by forgetting that while he himself can easily Mike's homework, Mike doesn't have his level of education and is thus confused, angered and humiliated by the 'easy' work he should feel bad about not finding fun. He also helps by threatening him with violence when the feeling that he's been given an impossible task by a sadistic teacher becomes unbearable. This complements how Elly helps by nagging about how he can't concentrate unless he's in an unearthly silence that he's not used to. They both help by being people who barely passed high school in the first place trying to cope with homework that leaves them baffled.
The reason that having John and Elly going over his homework with him is a rotten idea is that, well, a lot of why Mike can't do math all that well is that he had in Elly the worst possible coach. Since she doesn't want to admit that she and not evil, scary media is the primary influence in his life, she can't see that her screwing her face up and muttering about how math is for saps is why he still can't do basic mental arithmetic. It's akin to how someone who should be a contestant on Canada's Worst Driver insists on lovingly giving her weary charges their first driving lessons. Just as a woman who can barely count past ten is worthless when faced with algebra, having a nitwit who makes rolling stops inflict her ineptitude on her kids makes her the real error in the educational system.