The CAS Registry Mumber 444341-12-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 4,4,4,3,4 and 1 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 444341-12: (8*4)+(7*4)+(6*4)+(5*3)+(4*4)+(3*1)+(2*1)+(1*2)=122 122 % 10 = 2 So 444341-12-2 is a valid CAS Registry Number.