I know how important to account for every number accurately, @2000yearsago. 

This discrepancy usually happens because the program is rounding the decimal points. You may try checking the original price of your Item List from the Lists menu. This way, you'll be able to verify if you got the same price/cost shown in your report.

While the report shows the rounded number, the total amount always bases on the original price/cost of the item.

Let me also add an article about setting up multiple locations for tracking inventory: Multiple Inventory Sites.

Please let me know if you have other concerns. Have a great day.