The CAS Registry Mumber 111268-54-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,1,2,6 and 8 respectively; the second part has 2 digits, 5 and 4 respectively. Calculate Digit Verification of CAS Registry Number 111268-54: (8*1)+(7*1)+(6*1)+(5*2)+(4*6)+(3*8)+(2*5)+(1*4)=93 93 % 10 = 3 So 111268-54-3 is a valid CAS Registry Number.