Couple things there where you can see if it improves with the prompt/formatting. E.g. with Davinci (and J a bit but didn't test too much) you can get bette results by:

  - Using few-shot examples of similar length to the targets (e.g. 10 digit math, use 10 digit few shots)

  - Chunking numbers with commas

  - Having it double check itself

and here it's not doing any of those things.