The CAS Registry Mumber 110254-62-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,0,2,5 and 4 respectively; the second part has 2 digits, 6 and 2 respectively. Calculate Digit Verification of CAS Registry Number 110254-62: (8*1)+(7*1)+(6*0)+(5*2)+(4*5)+(3*4)+(2*6)+(1*2)=71 71 % 10 = 1 So 110254-62-1 is a valid CAS Registry Number.