The CAS Registry Mumber 596-92-9 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 5,9 and 6 respectively; the second part has 2 digits, 9 and 2 respectively. Calculate Digit Verification of CAS Registry Number 596-92: (5*5)+(4*9)+(3*6)+(2*9)+(1*2)=99 99 % 10 = 9 So 596-92-9 is a valid CAS Registry Number.