How are there twelve tribes if Levi is left out?

Levi is set apart and not counted among the twelve encamped tribes. The two sons of Joseph, Manasseh and Ephraim, are counted in place of Levi and Joseph, making up the twelve tribes. Thus the twelve tribes remain encamped in order around the tabernacle even though Levi is left out.

Les explains that the 12 tribes were all encamped in their order around the tabernacle. The tribe of Levi is left out here, and the two sons of Joseph, Manasseh and Ephraim, make up then the 12, even though Levi is left out. The 12 tribes are all encamped in order around the perimeter of the tabernacle. When the cloud lifted and moved, it would always course toward the east, and Judah, encamped right in front of the main gate, would always be the first tribe to go.

How were the 12 tribes arranged around the tabernacle, and why is Levi not counted?

The twelve tribes camped in their assigned order around the tabernacle perimeter, with Judah positioned in front of the main gate and always first to move when the cloud lifted. Levi was left out of this tribal count, while Joseph's two sons, Manasseh and Ephraim, made up the twelve tribes instead.