The CAS Registry Mumber 111210-64-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,1,2,1 and 0 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 111210-64: (8*1)+(7*1)+(6*1)+(5*2)+(4*1)+(3*0)+(2*6)+(1*4)=51 51 % 10 = 1 So 111210-64-1 is a valid CAS Registry Number.