The CAS Registry Mumber 22286-72-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,2,2,8 and 6 respectively; the second part has 2 digits, 7 and 2 respectively. Calculate Digit Verification of CAS Registry Number 22286-72: (7*2)+(6*2)+(5*2)+(4*8)+(3*6)+(2*7)+(1*2)=102 102 % 10 = 2 So 22286-72-2 is a valid CAS Registry Number.