Chronological Age (CA) Chronological age is noting but the actual calendar age of the child. The real age of the child in mental into consideration for testis called chronological age. Intelligent quotient The intelligent quotient represents the degree of brightness possessed by an individual. It expresses intelligent as the ratio of the metal age of the chronological age. When the mental age is divided by the chronological age and the quotient is multiplied by 100 the result is IQ. So the formula of finding out IQ is. MAI. QC. A The fraction is multiplied by 100 in order to remove the decimal point and to give the IQ. a value of 100 when mental age is equal with chronological age. This if the MA. is above the CAI. Q. will be above 100. If the MA. is less than the CA. the resulting IQ. will be less than 100. thus the scale has the same meaning from one age to another. IQ, may also be regarded as an index of brightness. The following table shows the relationship between IQ. and the degree of brightness given by Dr. Merrily based on the studies by Terman Merely Revision.