Numbers 1:20

English Standard Version

20 The people of Reuben, Israel’s firstborn, their generations, by their clans, by their fathers’ houses, according to the number of names, head by head, every male from twenty years old and upward, all who were able to go to war: (Nu 2:3) 

New International Version

20 From the descendants of Reuben the firstborn son of Israel: All the men twenty years old or more who were able to serve in the army were listed by name, one by one, according to the records of their clans and families. 

New International Reader’s Version

20 Here is the number of men from the tribe of Reuben. He is Israel’s eldest son. All the men able to serve in the army were counted. They were 20 years old or more. They were listed by name. They were listed one by one. They were listed according to the records of their tribes and families. 

King James Version

20 And the children of Reuben, Israel' eldest son, by their generations, after their families, by the house of their fathers, according to the number of the names, by their polls, every male from twenty years old and upward, all that were able to go forth to war;