The CAS Registry Mumber 116935-08-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,6,9,3 and 5 respectively; the second part has 2 digits, 0 and 8 respectively. Calculate Digit Verification of CAS Registry Number 116935-08: (8*1)+(7*1)+(6*6)+(5*9)+(4*3)+(3*5)+(2*0)+(1*8)=131 131 % 10 = 1 So 116935-08-1 is a valid CAS Registry Number.