Davinci model is rounding off numbers

Hi
I have a document in which the number is 1,561 million. When I ask gpt a question related to the answer, it tells me that it is 1.6 billion. How do I stop it to convert units. I am using davinci model

Thanks

Can you be a bit more descriptive ? Are you providing the document to GPT and then asking this question or are you straightway asking this ?

I am providing the document as a context to the model and then asking the question. Even I am specific to give me the number in million, it does not heed to it

Add it as a part of the instructions to GPT to return numerical values as accurate as possible from the document

Yes, I am giving it very accurate instructions like give me the numbers in million only