The CAS Registry Mumber 120125-40-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,0,1,2 and 5 respectively; the second part has 2 digits, 4 and 0 respectively. Calculate Digit Verification of CAS Registry Number 120125-40: (8*1)+(7*2)+(6*0)+(5*1)+(4*2)+(3*5)+(2*4)+(1*0)=58 58 % 10 = 8 So 120125-40-8 is a valid CAS Registry Number.