The CAS Registry Mumber 11147-86-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,1,1,4 and 7 respectively; the second part has 2 digits, 8 and 6 respectively. Calculate Digit Verification of CAS Registry Number 11147-86: (7*1)+(6*1)+(5*1)+(4*4)+(3*7)+(2*8)+(1*6)=77 77 % 10 = 7 So 11147-86-7 is a valid CAS Registry Number.