Question from Bryan:
How many children did Jacob have? 15?
Answer from Pastor Bob:
Jacob (whose name was changed to Israel) had 12 sons (see Genesis 29:31 -30:24 and 35:16-19.) He also had one daughter who was named, Dinah (Genesis 30:21), and there are references to other daughters, but they are not named (Genesis 37:35; 46:7). Thus he had more than 13 children, but we do not know the exact number. The 12 sons formed the twelve tribes of Israel.
Often, the two sons of Joseph (Jacob's grandsons) are each counted as a tribe. They were Ephraim and Manasseh. But the priestly tribe of Levi, which lived in cities and had no land, is left out of the count to keep the number at 12 tribes assigned portions of the Promised Land.
NOTE: Thanks to Pastor Donnie Brannen for pointing out the plural "daughters" in Genesis 37:35 and 46:7, which I missed and had to add here later.