The CAS Registry Mumber 332145-23-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,3,2,1,4 and 5 respectively; the second part has 2 digits, 2 and 3 respectively. Calculate Digit Verification of CAS Registry Number 332145-23: (8*3)+(7*3)+(6*2)+(5*1)+(4*4)+(3*5)+(2*2)+(1*3)=100 100 % 10 = 0 So 332145-23-0 is a valid CAS Registry Number.