The CAS Registry Mumber 47157-49-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,7,1,5 and 7 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 47157-49: (7*4)+(6*7)+(5*1)+(4*5)+(3*7)+(2*4)+(1*9)=133 133 % 10 = 3 So 47157-49-3 is a valid CAS Registry Number.