The CAS Registry Mumber 219650-29-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 2,1,9,6,5 and 0 respectively; the second part has 2 digits, 2 and 9 respectively. Calculate Digit Verification of CAS Registry Number 219650-29: (8*2)+(7*1)+(6*9)+(5*6)+(4*5)+(3*0)+(2*2)+(1*9)=140 140 % 10 = 0 So 219650-29-0 is a valid CAS Registry Number.