The CAS Registry Mumber 54878-00-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,4,8,7 and 8 respectively; the second part has 2 digits, 0 and 0 respectively. Calculate Digit Verification of CAS Registry Number 54878-00: (7*5)+(6*4)+(5*8)+(4*7)+(3*8)+(2*0)+(1*0)=151 151 % 10 = 1 So 54878-00-1 is a valid CAS Registry Number.