The CAS Registry Mumber 7576-25-2 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,5,7 and 6 respectively; the second part has 2 digits, 2 and 5 respectively. Calculate Digit Verification of CAS Registry Number 7576-25: (6*7)+(5*5)+(4*7)+(3*6)+(2*2)+(1*5)=122 122 % 10 = 2 So 7576-25-2 is a valid CAS Registry Number.