vim search numbers containing specific number of digits

There are different regular expression dialects; some (e.g. Perl's) do not require backslashes in the quantification modifier (\d{2}), some (e.g. sed) require two (\d\{2\}), and in Vim, only the opening curly needs it (\d\{2}). That's the sad state of incompatible regular expression dialects.

Also note that for matching exact numbers, you have to anchor the match so that \d\{2} won't match to digits (12) in 123. This can be done with negative look-behind and look-ahead:

\d\@<!\d\{2}\d\@!

Try the following:

\d\{2}

and you should use \ not /

You can find out more about the regular exression of vim on this site or in vim with :help regular.

Escaping brackets works: \d\{2\}