The CAS Registry Mumber 7714-03-6 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,7,1 and 4 respectively; the second part has 2 digits, 0 and 3 respectively. Calculate Digit Verification of CAS Registry Number 7714-03: (6*7)+(5*7)+(4*1)+(3*4)+(2*0)+(1*3)=96 96 % 10 = 6 So 7714-03-6 is a valid CAS Registry Number.