The CAS Registry Mumber 76318-69-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,6,3,1 and 8 respectively; the second part has 2 digits, 6 and 9 respectively. Calculate Digit Verification of CAS Registry Number 76318-69: (7*7)+(6*6)+(5*3)+(4*1)+(3*8)+(2*6)+(1*9)=149 149 % 10 = 9 So 76318-69-9 is a valid CAS Registry Number.