Job had seven sons and three daughters when his story begins:
Job 1:2 And there were born unto him seven sons and three daughters.
All of these children died in the calmaties that came upon Job at the beginning of the book. However at the end of the book, when Job was blessed, he had seven more sons and three more daughters.
Job 42:13 He had also seven sons and three daughters.
So, counting all his children, Job had fourteen sons and six daughters.
I hope you have found this helpful.