The CAS Registry Mumber 5877-04-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 5,8,7 and 7 respectively; the second part has 2 digits, 0 and 4 respectively. Calculate Digit Verification of CAS Registry Number 5877-04: (6*5)+(5*8)+(4*7)+(3*7)+(2*0)+(1*4)=123 123 % 10 = 3 So 5877-04-3 is a valid CAS Registry Number.