The CAS Registry Mumber 120239-95-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,0,2,3 and 9 respectively; the second part has 2 digits, 9 and 5 respectively. Calculate Digit Verification of CAS Registry Number 120239-95: (8*1)+(7*2)+(6*0)+(5*2)+(4*3)+(3*9)+(2*9)+(1*5)=94 94 % 10 = 4 So 120239-95-4 is a valid CAS Registry Number.