The CAS Registry Mumber 84920-79-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,9,2 and 0 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 84920-79: (7*8)+(6*4)+(5*9)+(4*2)+(3*0)+(2*7)+(1*9)=156 156 % 10 = 6 So 84920-79-6 is a valid CAS Registry Number.