The calculations are internal but they happen due to the orchestration of specific parts of the brain. That is to ask, why can't we consider our brains to be using their own internal tools?
I certainly don't think about multiplying two-digit numbers in my head in the same manner as when playing a Dm to a G7 chord that begs to resolve to a C!
It's not much different than ChatGPT being trained write a to Python script.
A notable difference is that it's much more efficient to teach something new to a 5-year old than fine-tune or retrain an LLM.
It appears LLMs got RHLFed into generating suitable Python scripts after the issue was exposed, which is an efficient way of getting better answers, but feels rather like handing the child really struggling with their arithmetic a calculator...