'Two and a half' in the Bible

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

The two and a half tribes have received their inheritance across the Jordan [River] opposite Jericho, eastward toward the sunrise.”

“Remember the word which Moses the servant of the Lord commanded you, saying, ‘The Lord your God is giving you rest (peace) and will give you this land [east of the Jordan].’