The CAS Registry Mumber 88674-83-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,8,6,7 and 4 respectively; the second part has 2 digits, 8 and 3 respectively. Calculate Digit Verification of CAS Registry Number 88674-83: (7*8)+(6*8)+(5*6)+(4*7)+(3*4)+(2*8)+(1*3)=193 193 % 10 = 3 So 88674-83-3 is a valid CAS Registry Number.