The CAS Registry Mumber 350716-64-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,5,0,7,1 and 6 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 350716-64: (8*3)+(7*5)+(6*0)+(5*7)+(4*1)+(3*6)+(2*6)+(1*4)=132 132 % 10 = 2 So 350716-64-2 is a valid CAS Registry Number.