Size is on the Format menu. It changes the font size of the currently selected text. If no text is highlighted, Size changes the font size at the insertion point. The Size submenu has the available sizes for the font currently installed in your System file. Font sizes in one view are independent of font sizes in another view. For example, a headline can be in 12-point and its corresponding bullet chart title can be in 18-point.
You can also choose font sizes from the keyboard by pressing cmd-shift-. (period) and cmd-shift-, (comma), for larger and smaller fonts, respectively. This works at the insertion point or on highlighted text.
You can change font size through the Rules window. As with other format rules, you define the scope of the rule for a range of levels from the selected headline, and if applied to headlines and/or document windows. The type-in box of the Rules window also lets you assign a font size that may not be in the Size submenu on the Format menu.