Help with dividing and rounding

It sounds simple, but I've yet to discover the answer.

I need to divide a group into hotel rooms, with four to a room. My

problem is: a group of 29, for example, would need 8 rooms. Standard

division and rounding, though, returns a result of 7 rooms.

The next step: We pay $25 for each "extra pillow". For example, my

group of 29 has three unused pillows, and would need to be billed an

additional $75 per night.

Question #1: How do a calculate and round a given group number so that

if it does not divide evenly by four it is rounded to the next higher

number?

Question #2: How do I calculate the number of unused pillows in a

group, and apply the $25 per pillow charge?

Thanks in advance, of course.

Dale Kendrick