The CAS Registry Mumber 5022-41-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 5,0,2 and 2 respectively; the second part has 2 digits, 4 and 1 respectively. Calculate Digit Verification of CAS Registry Number 5022-41: (6*5)+(5*0)+(4*2)+(3*2)+(2*4)+(1*1)=53 53 % 10 = 3 So 5022-41-3 is a valid CAS Registry Number.