The CAS Registry Mumber 70760-79-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,0,7,6 and 0 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 70760-79: (7*7)+(6*0)+(5*7)+(4*6)+(3*0)+(2*7)+(1*9)=131 131 % 10 = 1 So 70760-79-1 is a valid CAS Registry Number.