Frankly there is a lot of things that need to be changed in the education system in this country. In the US we don't have standards that are set at the national level, instead it is set at the state level, whereas funding is based upon income so a person in a wealthy or even an average neighborhood will have a better education then a person living in a poor neighborhood.
Teachers in the US are allowed to teach if they have a bachelors degree and they are allowed to teach a subject that isn't relevant to their degree, so a teacher who has a degree in Greek Mythology can teach math.
Then there are bad teachers who are protected by unions and "tenure", so a bad teacher who should be removed from the classroom is still allowed to teach,(I've had experience with this.) Classes should be based on the an individual students learning capabilities and placed into classes that way instead of the individual being forced to learn a subject in at the group level in which the individual might have difficulty learning that subject.
When my parents where in school A students where placed in their own class same thing with the B,C,D and F students. So why has that changed?
Then there's the state and federal tests, which seem to prove more of what a student hasn't learned then what they have learned. An example of which is when I lived in Washington State we would take the Washington Assessment of Student Learning or WASL for short. While I was in Jr. High or Middle School as its know in other states, I had been placed in a special class for math as I was horrible at it and the explanations from teachers never seemed to help much either. When it came time to take the WASL, I managed to do well in subjects like reading, social studies and English, but when it came time for the math section I could not answer most of the questions. Why? Because it was at a higher level of math then I had learned in the classroom and because it was a standardized test which meant that I was forced to be part of a group which had learned a higher level of math then I had and had a better comprehension of that level of math then I.