The CAS Registry Mumber 11075-16-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,1,0,7 and 5 respectively; the second part has 2 digits, 1 and 6 respectively. Calculate Digit Verification of CAS Registry Number 11075-16: (7*1)+(6*1)+(5*0)+(4*7)+(3*5)+(2*1)+(1*6)=64 64 % 10 = 4 So 11075-16-4 is a valid CAS Registry Number.