The AREAS function returns the number of areas in a reference. For example, =AREAS((A2:C3,B5:C7)) returns 2 areas.
The function has the following argument:
Reference – Required. A reference to a cell or a range of cells or a named range. For more than one references, an extra set of parentheses needed in the formula.
The following spreadsheet shows three simple examples of the AREAS function.
For more detail and examples, visit Microsoft office website.