The CAS Registry Mumber 1276539-32-2 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,2,7,6,5,3 and 9 respectively; the second part has 2 digits, 3 and 2 respectively. Calculate Digit Verification of CAS Registry Number 1276539-32: (9*1)+(8*2)+(7*7)+(6*6)+(5*5)+(4*3)+(3*9)+(2*3)+(1*2)=182 182 % 10 = 2 So 1276539-32-2 is a valid CAS Registry Number.