The CAS Registry Mumber 95307-16-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,5,3,0 and 7 respectively; the second part has 2 digits, 1 and 6 respectively. Calculate Digit Verification of CAS Registry Number 95307-16: (7*9)+(6*5)+(5*3)+(4*0)+(3*7)+(2*1)+(1*6)=137 137 % 10 = 7 So 95307-16-7 is a valid CAS Registry Number.