4/7th of the time, I would agree... Now, even though I put formulas with powers of four and even, if I recall, some logarithms in the World Builders Handbook, Traveller is supposed to be a Table Top RPG, and so having a paper design sheet with the ability to do math on paper should be a goal for most design systems (says the guy using an electronic calculator 40+ years ago to make Striker vehicles - when the adjective 'electronic was still necessary - so take that for what's it's worth).
Fairly round numbers and no more than two digits of detail is at least a good starting point.