[Freddy]

For the sake of clarity, and to avoid having a correctible error, I'm accustomed to always "paint the inner walls of the three-sided room." With ball between wrists, index finger upward, I say "one and one" to the players opposite table, then to the shooter, then to the players tableside. By this time both partners and the table have seen what I'm administering, offering at least three redundant opportunities for me to peer check the number of free throws. Each partner and the table flash back the number of throws.
Redundant, but effective.