Functions in MS Excel

Mathematical Functions

SUM - Adds up all the values in a range

SUMIF - Adds all the values in a range that meet specific criteria

SUMIFS (2007 and 2010 only) - Adds values in a range based on multiple criteria

SUMPRODUCT - Sum a range of cells that meet multiple criteria

ROUND - Round a number to a specified number of digits

ROUNDUP - Round a number up to a specified number of digits

ROUNDDOWN - Round a number down to a specified number of digits

CEILING - Round a number up to a multiple of significance

FLOOR - Round a number down to a multiple of significance

Statistical Functions

COUNT - Counts all the values in a range

AVERAGE - Calculates the average number from a range of values

MAX - Finds the maximum value in a range

MIN - Finds the minimum value in a range

COUNTA - Counts all non-empty cells in a range

COUNTBLANK - Counts all blank cells in a range

COUNTIF - Counts all the cells in a range that meet specific critera

COUNTIFS (2007 and 2010 only) - Counts all the cells in a range that meet multiple criteria

AVERAGEIF (2007 and 2010 only) - Calculates the average of a range of values that meet specific criteria

AVERAGEIFS (2007 and 2010 only) - Calculates the average of a range of values that meet multiple criteria

LARGE - Return a value dependent upon its ranking in a range of values in descending order

SMALL - Return a value dependent upon its ranking in a range of values in ascending order

RANK - Returns the rank or position of a number within a range of numbers

These are just some of the functions in MS Excel. And by some, I mean some. Instead of using symbols over and over again, you just have to type the equal sign (=), type the desired function, and enclose the range of cells. 

Examples:

=SUM(A1:C1)

=AVERAGE(D2:E2)