The CAS Registry Mumber 119509-49-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,9,5,0 and 9 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 119509-49: (8*1)+(7*1)+(6*9)+(5*5)+(4*0)+(3*9)+(2*4)+(1*9)=138 138 % 10 = 8 So 119509-49-8 is a valid CAS Registry Number.