The CAS Registry Mumber 4938-14-1 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,9,3 and 8 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 4938-14: (6*4)+(5*9)+(4*3)+(3*8)+(2*1)+(1*4)=111 111 % 10 = 1 So 4938-14-1 is a valid CAS Registry Number.