if you're units are based on 105 minutes, you can simplify the calculation of units.
local numbervar thisUnits;
thisUnits := ROUND(totalMinutes / 105)
all depends, if the estimate is for 130 minutes, how many units is it? Or can this not happen?
If 105 minutes is the 'unit' all you need to do is divide, so the if statement is simple...it is if there are any 'extra' minutes to account for, and how to do that.