The CAS Registry Mumber 132227-15-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,2,2 and 7 respectively; the second part has 2 digits, 1 and 5 respectively. Calculate Digit Verification of CAS Registry Number 132227-15: (8*1)+(7*3)+(6*2)+(5*2)+(4*2)+(3*7)+(2*1)+(1*5)=87 87 % 10 = 7 So 132227-15-7 is a valid CAS Registry Number.