Calculate hours and degrees fast and simple ! Insert hours, minutes and seconds directly using the separator key to distinguish the numbers. Insert hours, press separator, insert minutes, etc., then press the key of the operation you need to do (addition, subtraction, multiplication, division) and insert the other number; simply press '=' for the result. Same thing for degrees (regular and GPS). With '=' key you can repeat the latest operation. Choose between the possible customization of the number (hours:minutes:seconds or degreesminutes' seconds" or the new GPS degreesminutes'), and whether to show thousandths or not (via Settings -> Calc). Do you need to know how much time you took to accomplish a certain job ? Insert the finishing hour, press '-' key, insert starting hour e finally press '='. That's it ! Do you want to sum 1530' + 4215'35" + 9244' without having to do strange conversions and going directly to the result of 15029'35" ? Now you can ! Are you fond of astronomy and you need to calculate differences of longitudes or latitudes ? This is the app for you ! Use memory keys to obtain grand total when you have more complex calculations.