The CAS Registry Mumber 130458-05-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,0,4,5 and 8 respectively; the second part has 2 digits, 0 and 5 respectively. Calculate Digit Verification of CAS Registry Number 130458-05: (8*1)+(7*3)+(6*0)+(5*4)+(4*5)+(3*8)+(2*0)+(1*5)=98 98 % 10 = 8 So 130458-05-8 is a valid CAS Registry Number.