At their most basic level, computers excel at counting. Yet some Internet search engines do not. Several search engines have for a time stopped counting results at all. An advanced search on Lycos gives no total number, even though a regular Lycos search does. For a brief time, Excite stopped reporting the total number of hits, but then it put the numbers back in, although at a much smaller font size.
Most search engines provide the number of results for every search.
However, the numbers are not always accurate. First of all, they have to figure out what to count. A portal that gives results from several databases could count the hits from each one or the total hits from all. Another complicating factor appears when a search engine clusters by site. The simple approach would be to count sites as a separate number from pages, but the search engines that do cluster take several different approaches.