ABS (SQL Server Compact Edition)
Returns the absolute, positive value of the given numeric expression.
ABS ( numeric_expression )
Is an expression of the exact numeric or approximate numeric data type categories, or types that are implicitly convertible to float.
Returns the same type as numeric_expression except for the following expressions:
Nonnumeric types that can be implicitly converted to float
The following example returns the absolute value of the difference between the number of products in stock and number of products that have been ordered.
SELECT (UnitsInStock - UnitsOnOrder), ABS(UnitsInStock - UnitsOnOrder)