To use the first method, simply click on the header for column B, and then drag the mouse to the left. If you release the mouse button when the pointer is over the gray block that marks the intersection of the row and column headers (the blank gray block just above the row headers), then column B and everything to its left, including the hidden column A, are selected. You can then choose Column from the Format menu and then choose Unhide.

The second method is even niftier, provided you have a good eye and a steady mouse pointer. If you move your mouse pointer into the column header area, and then slowly move it to the left, you notice that it turns into a double-headed arrow with a blank spot in the middle as you position the pointer over the small area immediately to the left of the column B header. This double-headed arrow is a bit difficult to describe; it looks most closely like the double-headed arrow that appears when you position the pointer over the dividing line between column headers. It is different, however, because instead of a black line dividing the double arrows, there are two black lines with a gap between them.

When your mouse pointer changes to this special double-headed arrow, all you have to do is right-click and choose Unhide. Your previously missing column A magically reappears.