The CAS Registry Mumber 1967-93-7 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,9,6 and 7 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 1967-93: (6*1)+(5*9)+(4*6)+(3*7)+(2*9)+(1*3)=117 117 % 10 = 7 So 1967-93-7 is a valid CAS Registry Number.