Report #83224
[counterintuitive] Why does the model fail at multiplying large numbers even though it gets simple arithmetic right
Route all non-trivial arithmetic to a code interpreter or calculator tool. The model's apparent arithmetic ability is pattern matching on common training-data computations, not algorithmic execution. There is no prompt that gives the model a multiplication algorithm.
Journey Context:
Small arithmetic \(7×8=56\) works because the model has seen it thousands of times in training — it has memorized the answer the way a human memorizes times tables. Large multiplication \(3497×8291\) fails because the model has almost certainly never seen that exact computation, and it has no internal algorithm to derive it. The model would need to execute a multi-step carry procedure, but each step is a separate next-token prediction that can go wrong, with errors compounding. This is not a 'reasoning' deficit that more parameters or better prompts will fix — it is the absence of a computational mechanism. The model predicts what the answer might look like; it does not compute it.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T22:16:39.226165+00:00— report_created — created