The CAS Registry Mumber 17374-22-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,7,3,7 and 4 respectively; the second part has 2 digits, 2 and 2 respectively. Calculate Digit Verification of CAS Registry Number 17374-22: (7*1)+(6*7)+(5*3)+(4*7)+(3*4)+(2*2)+(1*2)=110 110 % 10 = 0 So 17374-22-0 is a valid CAS Registry Number.