The CAS Registry Mumber 126961-67-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,6,9,6 and 1 respectively; the second part has 2 digits, 6 and 7 respectively. Calculate Digit Verification of CAS Registry Number 126961-67: (8*1)+(7*2)+(6*6)+(5*9)+(4*6)+(3*1)+(2*6)+(1*7)=149 149 % 10 = 9 So 126961-67-9 is a valid CAS Registry Number.