The CAS Registry Mumber 167080-45-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,7,0,8 and 0 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 167080-45: (8*1)+(7*6)+(6*7)+(5*0)+(4*8)+(3*0)+(2*4)+(1*5)=137 137 % 10 = 7 So 167080-45-7 is a valid CAS Registry Number.