The CAS Registry Mumber 367518-79-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,6,7,5,1 and 8 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 367518-79: (8*3)+(7*6)+(6*7)+(5*5)+(4*1)+(3*8)+(2*7)+(1*9)=184 184 % 10 = 4 So 367518-79-4 is a valid CAS Registry Number.