Apple iWork '09 - Manual (Page 170)

ABS
The ABS function returns the absolute value of a number or duration.
ABS(num-dur)
 num-dur: A number or duration value. num-dur is a number or duration value.
Usage Notes
The result returned by ABS is either a positive number or 0. Â
Examples
=ABS(A1) returns 5, if cell A1 contains 5.
=ABS(8-5) returns 3.
=ABS(5-8) returns 3.
=ABS(0) returns 0.
=ABS(A1) returns 0, if cell A1 is empty.
Related Topics
For related functions and additional information, see:
“Listing of Numeric Functions” on page 167
“Value Types” on page 36
“The Elements of Formulas” on page 15
“Using the Keyboard and Mouse to Create and Edit Formulas” on page 26
“Pasting from Examples in Help” on page 41
CEILING
The CEILING function rounds a number away from zero to the nearest multiple of the
specified factor.
CEILING(num-to-round, multiple-factor)
 num-to-round: The number to be rounded. num-to-round is a number value.
 multiple-factor: The number to use to determine the closet multiple. multiple-factor
is a number value and must have the same sign as num-to-round.
170 Chapter 8 Numeric Functions