The CAS Registry Mumber 105202-60-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,5,2,0 and 2 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 105202-60: (8*1)+(7*0)+(6*5)+(5*2)+(4*0)+(3*2)+(2*6)+(1*0)=66 66 % 10 = 6 So 105202-60-6 is a valid CAS Registry Number.