The CAS Registry Mumber 109246-41-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,9,2,4 and 6 respectively; the second part has 2 digits, 4 and 1 respectively. Calculate Digit Verification of CAS Registry Number 109246-41: (8*1)+(7*0)+(6*9)+(5*2)+(4*4)+(3*6)+(2*4)+(1*1)=115 115 % 10 = 5 So 109246-41-5 is a valid CAS Registry Number.