The CAS Registry Mumber 2352-41-2 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,3,5 and 2 respectively; the second part has 2 digits, 4 and 1 respectively. Calculate Digit Verification of CAS Registry Number 2352-41: (6*2)+(5*3)+(4*5)+(3*2)+(2*4)+(1*1)=62 62 % 10 = 2 So 2352-41-2 is a valid CAS Registry Number.