In any business, rounding of invoice amount is a necessary feature. By default, Odoo ERP doesn't support this feature. But the 'Round off Invoice Amount' app from Cybrosys allows you to round off the invoice amount to the nearest whole amount by excluding the decimal parts. This application also supports you to create separate journal entries for the rounded amounts, which can assure the amount is balanced.
First, you have to download and Install the application form Odoo App Store. Then follow the below steps to enable the feature.
Here, the 'Total amount' is the actual amount. 'Amount Due' is the amount after rounding off the decimal parts and it is the one customer needs to pay.
As you can see in the picture a special journal entry is passed to balance the amount.