In Windows Excel 2010, how do I set up a worksheet to keep track of running time on projects. I have 3 different categories each with different times + a category with the total time for the project. (The time to arrange a book list is 26hours and 15mimutes + the time to move the books into a box is 10hours and 55minutes + the time to deliver the boxes is 31hours and 36minutes, the total time would be 68hours and 46minutes. I would like the format to be 26:15 + 10:55 + 31:36 = 68:46). So I have column “A” with the project title, column “B” with step one time in hours and minutes, column “C” with step two in hours and minutes, column “D” with step three in hours and minutes, and column “E” with total time of this project in hours and minutes (E=B+C+D).