The CAS Registry Mumber 22814-31-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,2,8,1 and 4 respectively; the second part has 2 digits, 3 and 1 respectively. Calculate Digit Verification of CAS Registry Number 22814-31: (7*2)+(6*2)+(5*8)+(4*1)+(3*4)+(2*3)+(1*1)=89 89 % 10 = 9 So 22814-31-9 is a valid CAS Registry Number.