The CAS Registry Mumber 119278-21-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,9,2,7 and 8 respectively; the second part has 2 digits, 2 and 1 respectively. Calculate Digit Verification of CAS Registry Number 119278-21: (8*1)+(7*1)+(6*9)+(5*2)+(4*7)+(3*8)+(2*2)+(1*1)=136 136 % 10 = 6 So 119278-21-6 is a valid CAS Registry Number.