And so, even by units analysis, if the units come out right, you've got a good shot that unless you've really, really messed up, that the answer is going to be right.

甚至在单位分析中，如果你的单位正确，你就能做的很有条理否则会一团糟，而注意了单位你的答案才有可能正确。

麻省理工公开课 - 固态化学导论课程节选