The CAS Registry Mumber 9005-93-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 9,0,0 and 5 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 9005-93: (6*9)+(5*0)+(4*0)+(3*5)+(2*9)+(1*3)=90 90 % 10 = 0 So 9005-93-0 is a valid CAS Registry Number.