Jacob’s first wife, Leah, bore him six sons: Reuben, Simeon, Levi, Judah, Issachar, and Zebulun. Each was the father of a tribe
That's 6 tribes.
Two other tribes, Gad and Asher, were named after sons born to Jacob and Zilpah, Leah’s maidservant. Two additional tribes, Dan and Naphtali, were named after sons of Jacob born of Bilhah, the maidservant of Rachel, Jacob’s second wife. Rachel bore Jacob two sons, Joseph and Benjamin.
That's another 6. Total 12
But Joseph produces 2 tribes. Efraim and Manasheh. There is no tribe Joseph.
So there should be 13.
Perhaps Levi doesn't count due to it's lack of territory. But the article clearly says that Levi is a tribe. And then go on pretending there are 12 tribes all along.
Is my Math correct?
This has been bothering me for years since childhood. I asked at http://hermeneutics.stackexchange.com/questions/11463/which-of-jacobs-son-dont-correpond-to-a-tribe?noredirect=1#comment21242_11463 and they all act as if it's obvious. Well, it's obviously fishy and nobody seems to think there is any problem.