The CAS Registry Mumber 25514-22-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,5,5,1 and 4 respectively; the second part has 2 digits, 2 and 2 respectively. Calculate Digit Verification of CAS Registry Number 25514-22: (7*2)+(6*5)+(5*5)+(4*1)+(3*4)+(2*2)+(1*2)=91 91 % 10 = 1 So 25514-22-1 is a valid CAS Registry Number.