A few years ago, due to an extreme math and science teacher shortage (still is), I taught a 7th and 8th grade math class in the public school system here.
ONE TIME WAS ENOUGH FOR ME.
I had kids who could not add fractions trying to take the pre-algebra based classes I was in charge of. Worse still, I had kids who could not divide. Forget about trying to teach turning fractions into decimals. Solving one step and two step problems was a joke.
Its a complex and multi-faceted problem (And no, Makaho, Vochers won't solve it either; some of those schools receiving them are just as inept; especially some of the charter schools).
Parents are a problem - I asked the five or six I would see on conference night (out of 100 students) if their child was studying the material at home and the standard reply was "I don't know" (my reply was "why don't you know?"). But they are quick to come and curse you out if the kid goes home and tells them you slighted them (some, not all: I did have some parents who were very supportive and cool).
Kids are a problem - many of them were more interested in wearing their pants down their butts, disrupting class doing stupid stuff, than trying to learn basic math. I told them many times that they had to learn some math even if it was only to count their money. They just didn't get it.
Some of the teachers were a problem. They did not hold the kids to any expectation of learning anything and would pass them for efforts that was so low it was a joke. This was because..........
The Administration was a problem. They put pressure on the teachers to pass them so that budgets would be maintained, passing rates would be acceptable, etc., etc. One teacher failed a percentage of the students that was deemed too high by the principal and he was placed on comprehensive evaluation when be refused to change the grades.
At the end of the year they asked me, no begged me to return. I just laughed and told them that it was a once in a lifetime experience and once was enough.
Oh yeah, Black male teacher catch it. Many of the students did not have fathers at home and for them strong black men were the enemy. You have to put your foot down and many of them really resented that.
One observation: I believe that math and science pullouts (i.e., separate classes for them away from the primary teacher) should begin as early as the third grade.
Regards.