The CAS Registry Mumber 925665-97-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 9,2,5,6,6 and 5 respectively; the second part has 2 digits, 9 and 7 respectively. Calculate Digit Verification of CAS Registry Number 925665-97: (8*9)+(7*2)+(6*5)+(5*6)+(4*6)+(3*5)+(2*9)+(1*7)=210 210 % 10 = 0 So 925665-97-0 is a valid CAS Registry Number.