The CAS Registry Mumber 47555-19-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,7,5,5 and 5 respectively; the second part has 2 digits, 1 and 9 respectively. Calculate Digit Verification of CAS Registry Number 47555-19: (7*4)+(6*7)+(5*5)+(4*5)+(3*5)+(2*1)+(1*9)=141 141 % 10 = 1 So 47555-19-1 is a valid CAS Registry Number.