The CAS Registry Mumber 122629-89-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,2,6,2 and 9 respectively; the second part has 2 digits, 8 and 9 respectively. Calculate Digit Verification of CAS Registry Number 122629-89: (8*1)+(7*2)+(6*2)+(5*6)+(4*2)+(3*9)+(2*8)+(1*9)=124 124 % 10 = 4 So 122629-89-4 is a valid CAS Registry Number.