Name of the sum of the components of an ordered pair

Question

Suppose a 2-dimensional point O, where O=(x1,y1). Is there a name for the scalar quantity x1+y1?

Thank you!

Answer 1

I'm unaware of such a scalar and I can't think of any reason one would sum these elements.

The x component of a vector is often added to the y component of a vector originating at, say the origin, and terminating at a point (x1, y1) and so we could say the vector has components (x1, y1), and, defining the x direction as i and the y direction as j, we define the vector as x1i + y1j but these are not scalar quantities and are not added together as scalars.