The CAS Registry Mumber 32337-45-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,2,3,3 and 7 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 32337-45: (7*3)+(6*2)+(5*3)+(4*3)+(3*7)+(2*4)+(1*5)=94 94 % 10 = 4 So 32337-45-4 is a valid CAS Registry Number.