The CAS Registry Mumber 19296-18-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,9,2,9 and 6 respectively; the second part has 2 digits, 1 and 8 respectively. Calculate Digit Verification of CAS Registry Number 19296-18: (7*1)+(6*9)+(5*2)+(4*9)+(3*6)+(2*1)+(1*8)=135 135 % 10 = 5 So 19296-18-5 is a valid CAS Registry Number.