Nomenclature of spiro compounds

Compounds where one carbon atom is common to two dissimilar rings are known as spiro compounds. The IUPAC or International Union of Pure and Applied Chemistry name for a spiro compound starts with the word spiro followed by square brackets consisting of the number of carbon molecules, in increasing order, in every ring connected to the common carbon atom and after that by the name of the parent hydrocarbon related to the total number of the carbon atoms in the two rings. The position of substituents are pointed out by numbers ; the numbering beginning along with the carbon atom adjacent to the spiro carbon and proceeding first around the smaller ring and then to the spiro atom and at last around the larger ring For example,