I think humans do two broad types of arithmetic: #1: For small numbers, the answer is "directly" available to us without consciously applying any steps #2: Fo

I think humans do two broad types of arithmetic: #1: For small numbers, the answer is "directly" available to us without consciously applying any steps #2: For larger numbers, we consciously apply some formal method to break the problem down into smaller steps of type #1. Like column addition, adding digit-by-digit and carrying the ones Despite seeming direct, I'd argue that if we could see at a low-level what our neurons were actually doing for #1, like to get 3 + 5, it would likely also look roundabout. Might even be a similar process as with LLMs, approximating magnitude (~7-9) then snapping to parity (even, since 3 and 5 are odd). LLMs should be capable of #2, including choosing an appropriate method, with chain-of-thought reasoning. But in addition to that, and I think what bongodongobob is getting at, is that LLMs appear to have a more robust #1 than us - being able to accurately add far larger numbers whereas we'd normally fall back to a step-by-step method after one or two digits.