The concept of "altogether" is expressed by the sign for TOTAL.
This also means "sum," or "add everything up."
TOTAL / sum up / altogether
Sentence: ALTOGETHER, HOW-MANY SIGN YOU KNOW?
Note: The above sentence relies on a lot of context (as if you were in
an ASL class and had been talking about learning sign language). In a
low context situation a more clear way to ask the question above would be:
DIFFERENT (shift) DIFFERENT SIGN ALTOGETHER YOU KNOW HOW-MANY YOU?
You can modify the sign ALTOGETHER to change it to mean "add to."
The non-dominant hand starts in a flattened "O"-hand stays stationary. The
dominant hand "adds to it."
Also see: ADD