The CAS Registry Mumber 2379-19-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,3,7 and 9 respectively; the second part has 2 digits, 1 and 9 respectively. Calculate Digit Verification of CAS Registry Number 2379-19: (6*2)+(5*3)+(4*7)+(3*9)+(2*1)+(1*9)=93 93 % 10 = 3 So 2379-19-3 is a valid CAS Registry Number.