Using a Numbered List
On the Agenda slide, you may replace the bullets with numbers by selecting all of the bulleted text and clicking on the Numbering button on the toolbar.
Another way to change bullet style is to highlight the bullets, right-click on them and select Bullets and Numbering. Click on the style of your choice and click on OK.
Note: Avoid the default bullet style and add interest to your slides with little arrow and checkmarks!