The CAS Registry Mumber 76454-62-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,6,4,5 and 4 respectively; the second part has 2 digits, 6 and 2 respectively. Calculate Digit Verification of CAS Registry Number 76454-62: (7*7)+(6*6)+(5*4)+(4*5)+(3*4)+(2*6)+(1*2)=151 151 % 10 = 1 So 76454-62-1 is a valid CAS Registry Number.