When it is necessary to convert the adjusted annual rate of pay to an hourly, daily, weekly, or biweekly rate, the following methods apply:
(a) To derive an hourly rate, divide the adjusted annual rate of pay by 2,087 and round to the nearest cent, counting one-half cent and over as a whole cent;
(b) To derive a daily rate, multiply the hourly rate by the number of daily hours of service required;
(c) To derive a weekly or biweekly rate, multiply the hourly rate by 40 or 80, as the case may be.