The CAS Registry Mumber 97394-25-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,7,3,9 and 4 respectively; the second part has 2 digits, 2 and 5 respectively. Calculate Digit Verification of CAS Registry Number 97394-25: (7*9)+(6*7)+(5*3)+(4*9)+(3*4)+(2*2)+(1*5)=177 177 % 10 = 7 So 97394-25-7 is a valid CAS Registry Number.