Function not getting the correct answer

I am trying to calculate payroll. I have 2 columns where regular hours and overtime hours are manually inputed. They are then multiplied by their respective pay per hour columns to come up with regular and overtime pay. The next column adds these to get total gross pay. That gross pay is then multiplied by the FICA and FICA Med factors to figure those taxes(2 different columns). I then have a column the adds all deductions to get total deductions(Fed,FICA,FICAMed,St). The last column subtracts total deductions from the gross pay column to get net income. My problem is the net pay column is $.01 off sometimes. I think what is happening is I obviously have all columns in dollar amounts with 2 decimal points. Some function columns have multiple decimal points in the answer and then are only showing the 2 decimal points. When those columns are used in the next equation, instead of using the dollar amount that is showing with 2 decimal points, it is remembering the multiple decimal points. This is resulting in being a penny off when I get to the end. How can I get the equations to use what actually shows in the columns(2 decimal points) instead of remembering multiple decimal places?

Hi,

Take a look at this link, looks like the problem is caused by not rounding on some of the calculations

http://www.cpearson.com/excel/rounding.htm