The CAS Registry Mumber 389600-94-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,8,9,6,0 and 0 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 389600-94: (8*3)+(7*8)+(6*9)+(5*6)+(4*0)+(3*0)+(2*9)+(1*4)=186 186 % 10 = 6 So 389600-94-6 is a valid CAS Registry Number.