The CAS Registry Mumber 3314-70-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 3,3,1 and 4 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 3314-70: (6*3)+(5*3)+(4*1)+(3*4)+(2*7)+(1*0)=63 63 % 10 = 3 So 3314-70-3 is a valid CAS Registry Number.