How many linen curtains formed the tabernacle itself?

Answer: Ten

The tabernacle was made of ten linen curtains with cherubim worked into them; eleven goat-hair curtains formed the tent over it.

““You are to construct the tabernacle itself with ten curtains of finely spun linen, each with blue, purple, and scarlet yarn, and cherubim skillfully worked into them. You are to make curtains of goat hair for the tent over the tabernacle—eleven curtains in all.”— Exodus 26:1, 26:7 (BSB)