What is the 1 that is carried called?
These are all Latin, would this make sense?
The Latin word for "carry" is "porto", would it be called Porto?
Just guessing here
Example:
123 <-- Augend or Addend
+ 9 <-- Addend
______
1 <-- What is this called?
123
+ 9
______
2
123
+ 9
______
132 <-- Sum