The CAS Registry Mumber 76924-96-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,6,9,2 and 4 respectively; the second part has 2 digits, 9 and 6 respectively. Calculate Digit Verification of CAS Registry Number 76924-96: (7*7)+(6*6)+(5*9)+(4*2)+(3*4)+(2*9)+(1*6)=174 174 % 10 = 4 So 76924-96-4 is a valid CAS Registry Number.