This is a script originally by mmmturkeybacon, modified by clickhappier. Mmmturkeybacon's script is helpful for HITs related to which search results are in which position, but if you prefer to have the default 10 results per page, it's written to only number the results with their 1-10 position on each page. If you display more than 10 results per page, you get the page number and the 1-10-on-the-page number in front of each result. I wanted the page number included on my 10-result numbering, to make it faster to keep track of which page I was on.
Google Instant (results-as-you-type) should be disabled to use this script, for each Google country domain you use. To disable Google Instant, go to the search results for anything, click on the Options gear in the upper right area of the page, click on the top choice "Search settings", set "Google Instant predictions" to "Never show Instant results.", and click the Save button at the bottom of the page.
v1, 2014-02-09 - mmmturkeybacon's original release on userscripts.org (imported to greasyfork on 2014-07-08)
v1c, 2014-07-02 - modified by clickhappier to add page numbering for 10-result pages
v1.0.1c, 2015-07-24 - Google's recent formatting changes broke it; rewrote it with jquery in the process of fixing it. I saw after finishing that mmmturkeybacon rewrote his version in Mar-Apr 2015 too, and had added 10-per-page support to it now as well as 'easy copy' and some other features, but I guess I'll keep this around anyway for those who prefer this version.
Related scripts: CH Google Color-Coded Results
; mmmturkeybacon Numbered Google Results with Easy Copy
See also: my MTG thread post
For many more MTurk-related userscripts, see the Turking Scripts set