The CAS Registry Mumber 74729-00-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,4,7,2 and 9 respectively; the second part has 2 digits, 0 and 0 respectively. Calculate Digit Verification of CAS Registry Number 74729-00: (7*7)+(6*4)+(5*7)+(4*2)+(3*9)+(2*0)+(1*0)=143 143 % 10 = 3 So 74729-00-3 is a valid CAS Registry Number.