Before hitting the start button, pause briefly to study the table. You can return to the table at any time by pressing the SPACEBAR. When the screen opens, you can press the graph button to activate the graph. Domain x is the small green x. Observe the action: as the value of domain x changes (from left to right), there is a corresponding change in the value of y (known as f(x)). The pen plots the curved path.
There are more examples: See Quadratic Graph 2 at https://scratch.mit.edu/projects/324056531 Quadratic Graph 3 at https://scratch.mit.edu/projects/104066603 and Quadratic Graph4 at https://scratch.mit.edu/projects/104133413
