The CAS Registry Mumber 4465-70-7 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,4,6 and 5 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 4465-70: (6*4)+(5*4)+(4*6)+(3*5)+(2*7)+(1*0)=97 97 % 10 = 7 So 4465-70-7 is a valid CAS Registry Number.