The CAS Registry Mumber 110259-12-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,0,2,5 and 9 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 110259-12: (8*1)+(7*1)+(6*0)+(5*2)+(4*5)+(3*9)+(2*1)+(1*2)=76 76 % 10 = 6 So 110259-12-6 is a valid CAS Registry Number.