The one thing that non-trinitarians don’t seem to get or refuse to accept is that we trinitarians do not believe that the Father, Son and Holy Ghost are three separate gods, but are facets of one God. It makes their whole argument invalid because it’s based on a false premise.
And let’s drop the mathematics. It’s like trying to describe the nature of the various colors based on their tactile hardness.
To continue with the quarter analogy. Ken, you are correct, the edge of the quarter is 100% quarter, but does not reveal the whole of the quarter. There is the heads and the tails that can’t be seen from the edge. The same can be said about the heads and the tails (viewpoint). In order to seen the entire quarter, you must look at from all angles.
The same is true of God. There is God (the spiritual facet), Jesus Christ (the physical facet) and the Holy Spirit (the connection between the two facet). Each alone is 100% God, but to “see” all of God, we need to look at him from all the angles he has revealed himself.