Round Up to Nearest Whole Number

Hi,

I was given a requirement to calculate the quantity of a product based on the number of system users. I wrote the conditional constraint in 7.8 as follows: 

"When possible, constrain the quantity of Server CAL = (((Number of System Users - 5) / 5) when the attribute Number of System Users > 5, otherwise Server CAL) to be true with a priority of 0"

The rule works, however I need to round up to the nearest whole number. So in essence ((8-5)/5) = 0.6 would be 1. Is there a way to roundup without scripting? I couldn't find a ROUNDUP math function like there is in MS Excel. 

Thanks,