The CAS Registry Mumber 12046-09-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,2,0,4 and 6 respectively; the second part has 2 digits, 0 and 9 respectively. Calculate Digit Verification of CAS Registry Number 12046-09: (7*1)+(6*2)+(5*0)+(4*4)+(3*6)+(2*0)+(1*9)=62 62 % 10 = 2 So 12046-09-2 is a valid CAS Registry Number.