To zoom in (enlarge) or zoom out (shrink):
Go to the View menu, and select Zoom.
A Zoom window will appear.
You can choose the amount of your sheet to display on your screen at one time. Select a Magnification percentage, or type your own in the Custom box. If you choose a small percentage, such as 50%, the size of the sheet's numbers and letters will be reduced to 50% of their actual size, and as a result, many cells can be displayed at once.
Note: If you are in Advanced Mode, there is another way to quickly zoom in and out. A Scale box is located near the top, right side of the Advanced toolbar (it contains the present zoom percentage). Click the down arrow on this box to select another zoom percentage, or type in your own. If you switch to Easy Mode, this zoom will be preserved.