I need to tweak my work schedule tracking formula in Excel- Currently it included "Time IN, Lunch Out, Lunch In, Time Out"

I currently have the following formula to track my work schedule. Time is put down in traditional format ie. 8:00 am, and is then totaled to show hours worked as a whole number 8, for 8 hrs worked and.. Below is the formula.

=IF(D2="","",ROUND(IF(OR(C2="",B2=""),(D2-A2),(B2-A2)+(D2-C2))*24*4,0)/4)

A=Time In , B=Lunch Out , C=Lunch In , D=Time Out.

I would like to alter this to in two ways

1st. Remove the ROUND function, I don't need it.

2nd. I don't need Lunch In and Out, I need column B to =Lunch, displayed as a whole number, 1 for one hour or, .5 for half hour. Which is subtracted from Time In and Time Out since we're not paid for lunch..

Thanks for any help, I'm totally lost on it, VERY new to excel and couldn't figure this out..