I teach the upper grades in my school, yet I continue to see kids who do not even have basic algebra skills in place. As a parent, I'm very aware of what my own children are learning in school. For the most part, I've been happy with their progress, but as they rise in grade level, I'm starting to see more emphasis on a loose understanding of the concepts and less emphasis on skills__particularly skills with arithmetic of fractions. The main problem with what I see with my students and my own children is that kids are taught "concepts" and are not taught skills__unless they're lucky enough to have a teacher who knows better. Most particularly, children are not taught mastery of arithmetic with fractions. Unfortunately, virtually all of their future math education depends on being able to do fractional arithmetic.
First, the Basics! The x axis of a graph refers to the horizontal line while the y axis refers to the vertical line. Together these lines form a cross and the point where they both meet is called the origin. The value of the origin is always 0. So if you move your pencil from the origin to the right, you are drawing a line across the positive values of the x axis, i.e., 1, 2, 3 and so on. From the origin to the left, you're moving across the negative values of the x axis, i.e., η, θ, ι and so on. If you go up from the origin, you are covering the positive values of the y axis. Going down from the origin, will take you to the negative values of the y axis.