The CAS Registry Mumber 92876-80-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,2,8,7 and 6 respectively; the second part has 2 digits, 8 and 0 respectively. Calculate Digit Verification of CAS Registry Number 92876-80: (7*9)+(6*2)+(5*8)+(4*7)+(3*6)+(2*8)+(1*0)=177 177 % 10 = 7 So 92876-80-7 is a valid CAS Registry Number.