The CAS Registry Mumber 11016-45-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,1,0,1 and 6 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 11016-45: (7*1)+(6*1)+(5*0)+(4*1)+(3*6)+(2*4)+(1*5)=48 48 % 10 = 8 So 11016-45-8 is a valid CAS Registry Number.