The CAS Registry Mumber 120807-79-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,0,8,0 and 7 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 120807-79: (8*1)+(7*2)+(6*0)+(5*8)+(4*0)+(3*7)+(2*7)+(1*9)=106 106 % 10 = 6 So 120807-79-6 is a valid CAS Registry Number.