The CAS Registry Mumber 65149-46-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,5,1,4 and 9 respectively; the second part has 2 digits, 4 and 6 respectively. Calculate Digit Verification of CAS Registry Number 65149-46: (7*6)+(6*5)+(5*1)+(4*4)+(3*9)+(2*4)+(1*6)=134 134 % 10 = 4 So 65149-46-4 is a valid CAS Registry Number.