There are several ways to change the point size of text to make the text larger or smaller. If you frequently resize text as you work, you can add Bigger and Smaller icons to the toolbar to resize text at the touch of a button.
First select the text or text box containing text that you want to resize.
Select the text you want to resize.
Choose Format > Font > Bigger. Or choose Format > Font > Smaller.
Choose View > Customize Toolbar.
Drag the Bigger and Smaller icons from the set of icons to the toolbar. You can place them wherever you want in the toolbar.
Click Done.
Clicking the Bigger or Smaller button changes the size of selected text by 1-point increments.
Click Fonts in the toolbar.
Select a font size or type the size you want into the Size field of the Fonts window.
For more information, see The Fonts Window.
If you’re having trouble with your text not fitting correctly within the placeholder text boxes, you can have Keynote automatically shrink text for you so that you don’t have to figure out what size to make it; see Automatically Shrinking Text.
If you want to create superscripts or subscripts, see Making Text Subscript or Superscript.