A string is any set of letters, or of letters and numbers. The only limitations are that strings cannot contain newlines. Put a single quote (') before strings beginning with a single quote ('), an at sign (@), plus (+), minus (-), or equals (=). See Figure 6-1 for an example of entering a string.

Numbers can be formatted as money, ($10.00), dates (11 Nov. 2002), or scientific notation (2.3e12). If you want a number to be displayed as a plain string without any number formatting, you can put a single quote (') before it.

Formulas are ways of describing a calculation you want Gnumeric to make automatically. Formulas always begin with a special character, which is usually the equals sign (=). You may also use the at symbol (@) or the plus or minus symbols (+ or -).

A cell reference is the part of a formula which refers to another cell. For example, in the formula to add two cells =(A4+A1), both A4 and A1 are cell references.