The additive routine adds the difference between the old and new values at the originating site to the current value at the destination site.
current value = current value + (new value - old value)
The additive conflict resolution method provides convergence for any number of master sites.
The average conflict resolution method averages the new column value from the originating site with the current value at the destination site.
current value = (current value + new value)/2
The average method cannot guarantee convergence if your replicated environment has more than one master. This method is useful for an environment with a single master site and multiple updatable snapshots.