'Two and a half' in the Bible

“They shall construct an ark of acacia wood two and a half cubits long, and one and a half cubits wide, and one and a half cubits high.

“You shall make a mercy seat of pure gold, two and a half cubits long and one and a half cubits wide.

Now Bezalel made the ark of acacia wood; its length was two and a half cubits, and its width one and a half cubits, and its height one and a half cubits;

He made a mercy seat of pure gold, two and a half cubits long and one and a half cubits wide.