The CAS Registry Mumber 124210-60-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,4,2,1 and 0 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 124210-60: (8*1)+(7*2)+(6*4)+(5*2)+(4*1)+(3*0)+(2*6)+(1*0)=72 72 % 10 = 2 So 124210-60-2 is a valid CAS Registry Number.