Financials - Rounding of Thousands

I have some financial statements prepared in excel, which have to be formated to the nearest $1,000.

However, I have come across several rounding issues with using sums to total balances, which I spends hours every month trying to correct by adding 500 here or there to get it all to balance (as you see the report, not what the true balance is).

I've done some looking around on the forums and see that I could changeh te 'Precision as Displayed' option under calculations. My only concern is that there is a lot of source data in these reports, and I'm concerned on the effect it might have on these sheets also.

What are the effects of chaning over the calculation method. Is there away to apply the calculation method to just a couple of the sheets?

I've attached an extract of the profit and loss is someone has a suggestion for a rounding or something.

Thanks in advance

Carrie