The CAS Registry Mumber 214833-26-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 2,1,4,8,3 and 3 respectively; the second part has 2 digits, 2 and 6 respectively. Calculate Digit Verification of CAS Registry Number 214833-26: (8*2)+(7*1)+(6*4)+(5*8)+(4*3)+(3*3)+(2*2)+(1*6)=118 118 % 10 = 8 So 214833-26-8 is a valid CAS Registry Number.