The CAS Registry Mumber 17825-62-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,7,8,2 and 5 respectively; the second part has 2 digits, 6 and 2 respectively. Calculate Digit Verification of CAS Registry Number 17825-62: (7*1)+(6*7)+(5*8)+(4*2)+(3*5)+(2*6)+(1*2)=126 126 % 10 = 6 So 17825-62-6 is a valid CAS Registry Number.