The CAS Registry Mumber 55454-37-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,5,4,5 and 4 respectively; the second part has 2 digits, 3 and 7 respectively. Calculate Digit Verification of CAS Registry Number 55454-37: (7*5)+(6*5)+(5*4)+(4*5)+(3*4)+(2*3)+(1*7)=130 130 % 10 = 0 So 55454-37-0 is a valid CAS Registry Number.