The CAS Registry Mumber 467-42-5 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 4,6 and 7 respectively; the second part has 2 digits, 4 and 2 respectively. Calculate Digit Verification of CAS Registry Number 467-42: (5*4)+(4*6)+(3*7)+(2*4)+(1*2)=75 75 % 10 = 5 So 467-42-5 is a valid CAS Registry Number.