Multiple choice IQ may be defined as MA/CA $\times$ 100 CA/MA $\times$ 100 MA/100 $\times$ CA MA $\times$ CA $\times$ 100 Reveal answer Fill a bubble to check yourself A Correct answer Explanation The classic formula for calculating the Intelligence Quotient (IQ) is Mental Age (MA) divided by Chronological Age (CA), multiplied by 100.