The CAS Registry Mumber 118050-15-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,8,0,5 and 0 respectively; the second part has 2 digits, 1 and 5 respectively. Calculate Digit Verification of CAS Registry Number 118050-15: (8*1)+(7*1)+(6*8)+(5*0)+(4*5)+(3*0)+(2*1)+(1*5)=90 90 % 10 = 0 So 118050-15-0 is a valid CAS Registry Number.