The CAS Registry Mumber 55000-37-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,5,0,0 and 0 respectively; the second part has 2 digits, 3 and 7 respectively. Calculate Digit Verification of CAS Registry Number 55000-37: (7*5)+(6*5)+(5*0)+(4*0)+(3*0)+(2*3)+(1*7)=78 78 % 10 = 8 So 55000-37-8 is a valid CAS Registry Number.