The CAS Registry Mumber 74074-19-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,4,0,7 and 4 respectively; the second part has 2 digits, 1 and 9 respectively. Calculate Digit Verification of CAS Registry Number 74074-19: (7*7)+(6*4)+(5*0)+(4*7)+(3*4)+(2*1)+(1*9)=124 124 % 10 = 4 So 74074-19-4 is a valid CAS Registry Number.