Addition
Addition is the aggregation of counts.
Addition builds on Counting. It is faster to think "3 and 5 is 8" than to count 1,2,3,4,5,6,7,8.
Addition shows you its true nature when you start working with things that are not numbers.
We can add two vectors to make a vector. We can add two matrices to make a matrix.
The two objects added must be of the same type and the result will be of that type.
In Tensorland there is a place where we only add differences. A difference is a change from a "before" to an "after". We may use subscripts 'f' and 'i' to signify initial and final.
When we see 5 + 7, we are looking at a story such as 5 from 11-6 and 7 from 18-11. Oh, and one more thing--in Tensorland every number is attached to a quantity such as a unit of length or mass or time.
