Numbered lists use the 1, 2, 3 numerical style by default. It’s possible to change the numbered list styles to something else such as a list using alphabets or Roman numerals — just like you change bulleted list styles. You can use several numerical styles in PowerPoint — there are variations in digits, alphabets, and Roman numerical styles.
Learn how to change the numbered list style of selected text in PowerPoint 2011 for Mac.

