The CAS Registry Mumber 86759-12-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,6,7,5 and 9 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 86759-12: (7*8)+(6*6)+(5*7)+(4*5)+(3*9)+(2*1)+(1*2)=178 178 % 10 = 8 So 86759-12-8 is a valid CAS Registry Number.