The CAS Registry Mumber 122951-45-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,2,9,5 and 1 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 122951-45: (8*1)+(7*2)+(6*2)+(5*9)+(4*5)+(3*1)+(2*4)+(1*5)=115 115 % 10 = 5 So 122951-45-5 is a valid CAS Registry Number.