The CAS Registry Mumber 73397-93-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,3,3,9 and 7 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 73397-93: (7*7)+(6*3)+(5*3)+(4*9)+(3*7)+(2*9)+(1*3)=160 160 % 10 = 0 So 73397-93-0 is a valid CAS Registry Number.