The CAS Registry Mumber 106366-67-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,6,3,6 and 6 respectively; the second part has 2 digits, 6 and 7 respectively. Calculate Digit Verification of CAS Registry Number 106366-67: (8*1)+(7*0)+(6*6)+(5*3)+(4*6)+(3*6)+(2*6)+(1*7)=120 120 % 10 = 0 So 106366-67-0 is a valid CAS Registry Number.