The CAS Registry Mumber 104707-07-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,4,7,0 and 7 respectively; the second part has 2 digits, 0 and 7 respectively. Calculate Digit Verification of CAS Registry Number 104707-07: (8*1)+(7*0)+(6*4)+(5*7)+(4*0)+(3*7)+(2*0)+(1*7)=95 95 % 10 = 5 So 104707-07-5 is a valid CAS Registry Number.