The CAS Registry Mumber 97152-45-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,7,1,5 and 2 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 97152-45: (7*9)+(6*7)+(5*1)+(4*5)+(3*2)+(2*4)+(1*5)=149 149 % 10 = 9 So 97152-45-9 is a valid CAS Registry Number.