Damion, firstly, you are a good man to come here seeking help for your wife and the boy.
As for your wife, there must be a special place in Heaven for the modern day teacher. I would not do this job for all the money in the world. The way kids are allowed to treat teachers nowadays is just disgusting.
I am a tool and die maker. I did not want to learn math and science when I was at school (long, long ago, in a place far, far away....

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I was not the studious type so I figured I would do a trade. In S.A. there was a mentality that if little Johnny is as dumb as a brick then let him do a trade...
Ha! I need math and science every day in my job and I have learned that the hard way.
Tell that boy that there are few things as mortifying as having to ask your sons to explain basic math to you or asking a collegue to do a simple trig. calculation so you can do your job. This is an inspiration to learn, I assure you. I have eaten large slices of humble pie and I have learned what I need to know now.
My math teacher tried everything he could to get me to learn this stuff, he has long since passed on but sometimes I see him in my minds eye and even though he was a gentleman I am sure he would have winked today and asked me if I would like some ketchup with my next serving of crow!!
Do whatever you must to get some sense into the kids head, I hope he is not as obstinate as I was back then, then your wife has a real battle on her hands....
Mike