> i dont understand why the teachers would go out of their way to reteach middle-school math.

"gaps" implies a critical mass of students who require middle-school math reteaching.

> i teach.

If you've taught for a non-trivial amount of time, you did one of the following with that class:

* graded on a curve so you don't fail half the class

* failed half the class, and got suspended (pours one out for my compsci professor in college who did that!)

Which was it?

>If you've taught for a non-trivial amount of time,

i have

>you did one of the following with that class: [...] Which was it?

these are not the only two options.