20 Excel Formula

http://www.databison.com/index.php/20-useful-excel-formulas-you-must-know/

DATEVALUE = Converts a date in the form of text to a serial number
DAY = Converts a serial number to a day of the month
MONTH = Converts a serial number to a month
YEAR = Converts a serial number to a year
LEFT = Returns the leftmost characters from a text value
LEN = Returns the number of characters in a text string
RIGHT = Returns the rightmost characters from a text value
AVERAGE = Returns the average of its arguments
COUNT = Counts how many numbers are in the list of arguments
COUNTIF = Counts the number of nonblank cells within a range that meet the given criteria
MAX = Returns the maximum value in a list of arguments
AND = Returns TRUE if all its arguments are TRUE
IF = Specifies a logical test to perform
ROUNDDOWN = Rounds a number down, toward zero
ROUNDUP = Rounds a number up, away from zero
SUM = Adds its arguments
SUMIF = Adds the cells specified by a given criteria
OFFSET = Returns a reference offset from a given reference
VLOOKUP = Looks in the first column of an array and moves across the row to return the value of a cell
ISERROR = Returns TRUE if the value is any error value