Each of those topics - from adding and subtracting to fractions and decimals - is approached in three different stages.

VOA: standard.2010.08.10

In principle, you could bill your clients for fractions of a second or fractions of a minute.

原则上,你可以按分钟或者按秒钟,从你的客户那里收取费用

耶鲁公开课 - 博弈论课程节选