Apple Numbers '08 - Manual (Page 252)

252 Chapter 12 Dictionary of Functions
MROUND
The MROUND function rounds a number to the nearest multiple of a specified factor.
MROUND(number, factor)
 number: The number you want to round. It can be a numeric expression, or a
reference to a cell containing a numeric expression.
 factor: The number whose multiples you want to round to.
Notes
Relative number size is based on magnitude (distance from 0).
Both arguments must have the same sign.
NOT
The NOT function evaluates the truth value of an expression and then returns the
reverse. If the expression is true, the function returns FALSE; if the expression is false,
the function returns TRUE.
NOT(expression)
 expression: A logical or numeric expression.
Notes
If expression is a numeric expression, a value of 0 is interpreted as false and any nonzero
value is interpreted as true.
Examples
MROUND(2, 3) returns 3.
MROUND(4, 3) returns 3.
MROUND(4.4999, 3) returns 3.
MROUND(4.5, 3) returns 6.
MROUND(-4.5, 3) returns an error.
Examples
NOT(0) returns TRUE because 0 in interpreted as FALSE.
OR(A9, NOT(A9)) always returns TRUE because either A9 or its opposite will always be true.
NOT(OR(FALSE,FALSE)) mimics a logical NOR. In this case, it returns TRUE because neither argument of
the logical OR is true.