The CAS Registry Mumber 4713-41-1 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,7,1 and 3 respectively; the second part has 2 digits, 4 and 1 respectively. Calculate Digit Verification of CAS Registry Number 4713-41: (6*4)+(5*7)+(4*1)+(3*3)+(2*4)+(1*1)=81 81 % 10 = 1 So 4713-41-1 is a valid CAS Registry Number.