In order to set rounding rules for the categories, follow the steps below:
1. Navigate to Catalog from the left sidebar.
2. Expand the Categories menu and select the store where marked up category prices.
3. Select the needed category and click the Edit icon.
4. You will be taken to the information page, scroll down to Rounding rules and click Add rule.
5. As an example we added a rounding rule to change the Prices that end between 0.01 And 0.50 Should end with 0.00.
6. Once you're done add as many rounding rules as you need, and make sure to click Save Category.
Here is an example:
This product is $ 11.33 in the store.
Here's how it be visible to your customers after saving the rule.
That's it! Learn more about how to set rounding rules for departments here.