[linuxftw]

In the 6th grade, you were mentally developed enough to understand some of the basic concepts of algebra. Someone (most) in the 3rd or 4th grade isn't developed enough to understand those concepts. This would be analogous to teaching elementary school students latin roots, it just doesn't make much sense, and their ability to dissect particular words is of little to no value at that stage in their development.

[eitally]

This isn't true. Kids start learning algebraic concepts in roughly 2nd grade, and are well-acquainted with the concept of variables, algorithms, order of operations, roots & exponents, converting fractions to decimals & vice versa, etc before they get out of 5th grade. The only fundamental key concept I don't think they're taught, that is critical in algebra 1, is how to solve systems of equations.