Have you ever wished for the power to tweak scale right from the keyboard? No twirling down three layers just to access the Scale sliders? You can adjust layer size quickly using the numeric keypad.
To nudge scale larger, press Cmd+the plus sign on the numeric keypad (Ctrl+the plus sign on the numeric keypad).
To nudge scale smaller press Cmd+the minus sign on the numeric keypad (Ctrl+the minus sign on the numeric keypad).
Add the Shift key to the above combinations to scale more quickly.