The display of listing (auction and classified) counts that display next to a category within any category navigation depends on the category navigation you are using. There are two types of category navigation within the software. There is category navigation that's included within the {body_html} tag within the front page and category browsing pages. There's also category navigation that can be displayed by placing a category navigation module within pages. We'll cover count display within both types.
By default (within the default design) the software displays the category navigation on the front page and category navigation features through the {body_html} tag. So if you have not changed this at all look to control the display of category counts through the following admin tool controls
SITE SETUP > BROWSING SETTINGS > Display Category/Subcategory Counts SITE SETUP > BROWSING SETTINGS > Listing Type Order for Category Counts
The latter setting allows you to display category counts with the following options:
Here is a screenshot showing those options:
If you have replaced any of the default "body html" category navigation or simply placed a category navigation module to affect that specific category navigation module you make changes in it's admin tool. You can find all category navigation module admin tools in one section of the Geo admin tool here:
PAGE MODULES > BROWSING > CATEGORY NAVIGATION
Once there you would click into the admin tool for the category navigation you placed within your site. The category navigation 1 module admin tool is shown below but all are essentially the same:
You'll see the same display options you see in the previous section.