Simple As Math

Math, math is simple. 
You add or you subtract, 
It seems as simple as that
But then there's variables 
And parenthesis 
And all these other little symbols
That mean absolutely nothing to you
But you teacher says that the way it goes
So you go along 
Though you don't understand
Why you have to get rid of the variable 
And divide x
Or find the mean
And the radius of a circle
Why some numbers get to skip 
And others have to be held back
And removed, divided and subtracted
Till a zero takes it's place
Math used to be simple.