The CAS Registry Mumber 109759-02-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,9,7,5 and 9 respectively; the second part has 2 digits, 0 and 2 respectively. Calculate Digit Verification of CAS Registry Number 109759-02: (8*1)+(7*0)+(6*9)+(5*7)+(4*5)+(3*9)+(2*0)+(1*2)=146 146 % 10 = 6 So 109759-02-6 is a valid CAS Registry Number.