In Excel 2010, the MODE function has been renamed as MODE.SNGL.
Although it has been replaced, the Mode function is still available in Excel 2010 (stored in the list of compatibility functions), to allow compatibility with earlier versions of Excel.
The Excel MODE function returns the statistical mode (the most frequently occurring value) of a list of supplied numbers. If there are 2 or more most frequently occurring values in the supplied data, the function returns the lowest of these values
The format of the function is:
where the number arguments are a set of one or more numeric values, or arrays of numeric values, for which you want to calculate the mode.
In current versions of Excel (Excel 2007 and later), you can supply up to 255 number arguments to the Mode function, but in Excel 2003, the function can only accept up to 30 number arguments.
Text and logical values within a supplied array are ignored by the function.
The following example shows the Mode function, used to calculate the mode of the set of values in cells A1  A10.
Formulas:
 Results:

Note that the data in column A of the example spreadsheet has two statistical modes, 3 and 4. Therefore, the Mode function returns the lowest of these two values.
Further information and examples of the Excel Mode function can be found on the Microsoft Office website.
If you get an error from the Excel Mode function this is likely to be one of the following:
#NUM!    Occurs if there are no duplicates (and there is therefore no mode) within the supplied values. 
#VALUE!    Occurs if a value that is supplied directly to the function (i.e. not part of an array of supplied values) is nonnumeric. 