This is Tutorial on the x and Y position. Scratch's coordinate system uses 2 coordinates, "X position" and "Y position", to determine the location of a sprite on the stage. The "X position" value determines the horizontal location of the sprite and the "Y position" value determines the vertical location or height. The screen is a 480x360 rectangle, such that: the X position can range from 240 to -240, where 240 is the rightmost a sprite can be and -240 is the leftmost, and the Y position can range from 180 to -180, where 180 is the highest it can be and -180 is the lowest it can be.
The only changes I made was the sprite Description of X and Y coordinates from Scratch Wiki. Additional changes made on 2/23/17: Added Ball sprite for students to use in the lesson. Will ask the students to move the ball to a specific place on the stage. They will use the U, D, R, L keys to move. They will see X & Y ball position variable to confirm the correct spot on the stage.
