Clearly, therefore, twelve thousand was the figurative duodecimal equivalent of the decimal a hundred thousand. The Humphrey point is sometimes used instead of a decimal point in duodecimal numbers. Decimal time was used in China throughout most of its history alongside duodecimal time. Roman fractions were based on a duodecimal system. Languages using duodecimal number systems are uncommon. Duodecimal numeric systems have some practical advantages over decimal. It is half a gross or 6 dozen (i.e., 60 in duodecimal). Janji has, or had, a duodecimal number system. They use the word "dozenal" instead of "duodecimal" to avoid the more overtly base-ten terminology. Historically, units of time in many civilizations are duodecimal. In duodecimal, however, 11 is sometimes represented as E and ten as T or X. As a result, duodecimal has been described as the optimal number system. This section is about the divisibility rules in duodecimal.