The CAS Registry Mumber 3941-50-2 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 3,9,4 and 1 respectively; the second part has 2 digits, 5 and 0 respectively. Calculate Digit Verification of CAS Registry Number 3941-50: (6*3)+(5*9)+(4*4)+(3*1)+(2*5)+(1*0)=92 92 % 10 = 2 So 3941-50-2 is a valid CAS Registry Number.