Apple Numbers '08 - Manual (Page 228)

228 Chapter 12 Dictionary of Functions
DISC
The DISC function calculates the discount rate of a security.
DISC(settle, maturity, price, value, [day-count])
 settle: The date of the settlement, usually the date when the security was purchased.
 maturity: The date the security matures (expires).
 price: The cost of the security per $100 par value.
 value: The redemption value per $100 par value.
 day-count: Optional; specifies the number of days per month and days per year used
in the calculations (sometimes called the day count basis).
0 or omitted uses 30/360 (30 days for each month, 360 days in a year).
1 uses actual/actual (the number of days shown on a calendar).
2 uses actual/360 (calendar days for each month but 360 days per year).
3 uses actual/365 (calendar days for each month but 365 days per year).
4 uses 30E/360 (European 30/360).
DOLLAR
The DOLLAR function converts a number to a string written as a dollar amount with
the specified number of decimal places.
DOLLAR(number, [places])
 number: The number you want to convert. It can be a number, numeric expression,
or a reference to a cell containing a numeric expression.
 places: Optional; a positive number represents the number of digits you want to
have to the right of the decimal point. If omitted, 2 is assumed. A negative number
specifies digits to round to the left of the decimal point.
Notes
The DOLLAR function uses standard arithmetical rounding; if the most significant digit
being dropped is 5 or greater, the result is rounded up.
Examples
If A1:E1 contain 1/1/2000, 1/1/2001, 90, 100, 0:
DISC(A1, B1, C1, D1, E1) returns 10%.
DISC(A1, B1, 80, D1, E1) returns 20%.
DISC(A1, B1, C1, 110, E1) returns 18%.