'Two and a half' in the Bible

And they are to make an ark of hard wood; two and a half cubits long, and a cubit and a half wide and high.

And you are to make a cover of the best gold, two and a half cubits long and a cubit and a half wide.

And Bezalel made the ark of hard wood, two and a half cubits long, a cubit and a half wide and a cubit and a half high;

And he made the cover all of gold, two and a half cubits long and a cubit and a half wide.