The CAS Registry Mumber 84860-34-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,8,6 and 0 respectively; the second part has 2 digits, 3 and 4 respectively. Calculate Digit Verification of CAS Registry Number 84860-34: (7*8)+(6*4)+(5*8)+(4*6)+(3*0)+(2*3)+(1*4)=154 154 % 10 = 4 So 84860-34-4 is a valid CAS Registry Number.