The CAS Registry Mumber 83792-77-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,3,7,9 and 2 respectively; the second part has 2 digits, 7 and 7 respectively. Calculate Digit Verification of CAS Registry Number 83792-77: (7*8)+(6*3)+(5*7)+(4*9)+(3*2)+(2*7)+(1*7)=172 172 % 10 = 2 So 83792-77-2 is a valid CAS Registry Number.