 Similarly, the words for 98 and 99 were "duodecentum" (two from hundred) and "undecentum" (one from hundred), respectively.However, the explanation does not seem to apply to and , since the Latin words for 17 and 97 were "septendecim" (seven ten) and "nonaginta septem" (ninety seven), respectively.Another example of irregular subtractive notation is the use of for 18.