The CAS Registry Mumber 32373-06-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,2,3,7 and 3 respectively; the second part has 2 digits, 0 and 6 respectively. Calculate Digit Verification of CAS Registry Number 32373-06: (7*3)+(6*2)+(5*3)+(4*7)+(3*3)+(2*0)+(1*6)=91 91 % 10 = 1 So 32373-06-1 is a valid CAS Registry Number.