Counting adverbs are provided in this article. The words listed here are commonly found along with the verb counting in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb COUNTING.
actually, carefully
mentally, merely
probably, really
silently, simply
slowly
Hope this word list had the counting adverb you were looking for. In addition to adverbs used with counting, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.