The CAS Registry Mumber 16134-70-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,6,1,3 and 4 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 16134-70: (7*1)+(6*6)+(5*1)+(4*3)+(3*4)+(2*7)+(1*0)=86 86 % 10 = 6 So 16134-70-6 is a valid CAS Registry Number.