I don't think this problem should be solved. Children need to understand the subject and do their home work; If they couldn't then the real problem is not the lack of problem solver but lack of proper tutors which are being addressed by numerous free solutions e.g. https://www.khanacademy.org/ .

I presume you are child yourself and so I want to stress that my comment shouldn't discourage you from finding need-gaps which is a valuable quality.