The CAS Registry Mumber 6367-12-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 6,3,6 and 7 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 6367-12: (6*6)+(5*3)+(4*6)+(3*7)+(2*1)+(1*2)=100 100 % 10 = 0 So 6367-12-0 is a valid CAS Registry Number.