The CAS Registry Mumber 139471-06-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,9,4,7 and 1 respectively; the second part has 2 digits, 0 and 6 respectively. Calculate Digit Verification of CAS Registry Number 139471-06: (8*1)+(7*3)+(6*9)+(5*4)+(4*7)+(3*1)+(2*0)+(1*6)=140 140 % 10 = 0 So 139471-06-0 is a valid CAS Registry Number.