The CAS Registry Mumber 12254-64-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,2,2,5 and 4 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 12254-64: (7*1)+(6*2)+(5*2)+(4*5)+(3*4)+(2*6)+(1*4)=77 77 % 10 = 7 So 12254-64-7 is a valid CAS Registry Number.