The CAS Registry Mumber 1132-70-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,1,3 and 2 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 1132-70: (6*1)+(5*1)+(4*3)+(3*2)+(2*7)+(1*0)=43 43 % 10 = 3 So 1132-70-3 is a valid CAS Registry Number.