For the age is divided into twelve parts, and nine of its parts have already passed, as well as half of the tenth part; so two of its parts remain, besides half of the tenth part: The conjunction For introduces the reason why the world is considered no longer young. Both Good News Bible and Contemporary English Version leave this connector implied. It may be rendered “You see.” The age here clearly refers to the whole period of human history. The age is divided into twelve parts may be translated “human history is divided into twelve parts” or “we may divide human history into twelve parts.” The textual problems mentioned in Revised Standard Version‘s footnotes are easily resolved by following Good News Bible‘s approach to these verses, and they are of interest only to scholars, so translators may ignore them. A model that combines verses 11 and 12 is:

• You see, human history is divided into twelve parts, and we are now halfway through the tenth part. Only two parts remain, plus the other half of the tenth one.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.