The CAS Registry Mumber 83622-79-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,3,6,2 and 2 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 83622-79: (7*8)+(6*3)+(5*6)+(4*2)+(3*2)+(2*7)+(1*9)=141 141 % 10 = 1 So 83622-79-1 is a valid CAS Registry Number.