18 and they called the whole community together on the first day of the second month. The people registered their ancestry by their clans and families, and the men twenty years old or more were listed by name, one by one,

Read Numbers 1:18 Using Other Translations

And they assembled all the congregation together on the first day of the second month, and they declared their pedigrees after their families, by the house of their fathers, according to the number of the names, from twenty years old and upward, by their polls.
and on the first day of the second month, they assembled the whole congregation together, who registered themselves by clans, by fathers' houses, according to the number of names from twenty years old and upward, head by head,
and they assembled the whole community of Israel on that very day. All the people were registered according to their ancestry by their clans and families. The men of Israel who were twenty years old or older were listed one by one,