The CAS Registry Mumber 57498-33-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,7,4,9 and 8 respectively; the second part has 2 digits, 3 and 3 respectively. Calculate Digit Verification of CAS Registry Number 57498-33: (7*5)+(6*7)+(5*4)+(4*9)+(3*8)+(2*3)+(1*3)=166 166 % 10 = 6 So 57498-33-6 is a valid CAS Registry Number.