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