The CAS Registry Mumber 123027-49-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,3,0,2 and 7 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 123027-49: (8*1)+(7*2)+(6*3)+(5*0)+(4*2)+(3*7)+(2*4)+(1*9)=86 86 % 10 = 6 So 123027-49-6 is a valid CAS Registry Number.