The CAS Registry Mumber 86179-52-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,6,1,7 and 9 respectively; the second part has 2 digits, 5 and 2 respectively. Calculate Digit Verification of CAS Registry Number 86179-52: (7*8)+(6*6)+(5*1)+(4*7)+(3*9)+(2*5)+(1*2)=164 164 % 10 = 4 So 86179-52-4 is a valid CAS Registry Number.