The CAS Registry Mumber 79700-92-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,9,7,0 and 0 respectively; the second part has 2 digits, 9 and 2 respectively. Calculate Digit Verification of CAS Registry Number 79700-92: (7*7)+(6*9)+(5*7)+(4*0)+(3*0)+(2*9)+(1*2)=158 158 % 10 = 8 So 79700-92-8 is a valid CAS Registry Number.