The CAS Registry Mumber 120446-13-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,0,4,4 and 6 respectively; the second part has 2 digits, 1 and 3 respectively. Calculate Digit Verification of CAS Registry Number 120446-13: (8*1)+(7*2)+(6*0)+(5*4)+(4*4)+(3*6)+(2*1)+(1*3)=81 81 % 10 = 1 So 120446-13-1 is a valid CAS Registry Number.