Vectors as real numbers

What is a number line? It is a way to make give all numbers a position from left to right. But we may also assign numbers to shifts along that line, as a directed length of the arrow. Compare the length and direction of the arrow to the position of the solid dot. What do you notice? How might this idea help you think about adding numbers?
Grab the "tail" point of the vector (open dot) and move it. Attend to what changes as you do so and what does not change. Grab the number-as-position point (solid dot) and move it. Attend to what changes as you do so.