The CAS Registry Mumber 58525-86-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,8,5,2 and 5 respectively; the second part has 2 digits, 8 and 6 respectively. Calculate Digit Verification of CAS Registry Number 58525-86: (7*5)+(6*8)+(5*5)+(4*2)+(3*5)+(2*8)+(1*6)=153 153 % 10 = 3 So 58525-86-3 is a valid CAS Registry Number.