If you have the cursor over the variable in question, you can press * and it will search for the next occurrence or # will search for the previous one.
This is equivalent to typing:
/\<n\>
(\< matches on the start of a word and \> matches on the end of word). The only difference (for reasons I’m not sure of) is that * and # don’t pay attention to the 'smartcase' option.
See:
:help *
:help /\<