What is a function browser?

Concepts

What are the most useful functions?

The list of functions presented by the function browser is quite long. There are only a few of these functions that are used most frequently. Some of the most useful functions are:

Statistical functions:

AVERAGE(number1,number2,...): Calculates the average of the values in a range of cells.
STDEV(number1,number2,...): Calculates the standard deviation of the range of cells.
VAR(number1,number2,...): Calculates the variance of the range of cells.
SUM(number1,number2,...): Calculates the sum of the range of cells.

Mathematical functions:

ROUND(number, Number of Places): Rounds the number x to the specified number of places.
ABS(<value>): Returns the absolute value of <value>.
MAX(number1,number2,...): Returns the largest value in number1,number2,.... (There is also a MIN)

Financial functions are covered in a separate concept.)

There are also many Financial and Date/Time functions. You could refer to the function browser to get a list of all the functions