The CAS Registry Mumber 74992-36-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,4,9,9 and 2 respectively; the second part has 2 digits, 3 and 6 respectively. Calculate Digit Verification of CAS Registry Number 74992-36: (7*7)+(6*4)+(5*9)+(4*9)+(3*2)+(2*3)+(1*6)=172 172 % 10 = 2 So 74992-36-2 is a valid CAS Registry Number.