The CAS Registry Mumber 97573-41-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,7,5,7 and 3 respectively; the second part has 2 digits, 4 and 1 respectively. Calculate Digit Verification of CAS Registry Number 97573-41: (7*9)+(6*7)+(5*5)+(4*7)+(3*3)+(2*4)+(1*1)=176 176 % 10 = 6 So 97573-41-6 is a valid CAS Registry Number.