The CAS Registry Mumber 50995-25-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,0,9,9 and 5 respectively; the second part has 2 digits, 2 and 5 respectively. Calculate Digit Verification of CAS Registry Number 50995-25: (7*5)+(6*0)+(5*9)+(4*9)+(3*5)+(2*2)+(1*5)=140 140 % 10 = 0 So 50995-25-0 is a valid CAS Registry Number.