For counting r's in strawberry, what should the instruction make explicit?

Answer: The unit is letters

The unit is tokens — Tokens are exactly the model-facing unit, which makes this a tempting answer. But the user is not asking how the model internally chunks strawberry; the user wants the number of visible r letters. The surprise is that the right prompt must pull the task back from model units to human text units.

The unit is letters ✓ — This choice states the unit humans intended: individual letters. Tokenization sources show that models process chunks, while counting studies show that letter counting can still be hard. The surprise is that a tiny word question depends on naming the low-level unit clearly.

The unit is syllables — Syllables are a plausible human unit for spoken words, but they do not answer a written letter-counting task. The r's in strawberry are visual characters, not beats of pronunciation. This distractor shows why naming the exact unit matters: sound units, token units, and letter units are not interchangeable.