The CAS Registry Mumber 3376-37-2 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 3,3,7 and 6 respectively; the second part has 2 digits, 3 and 7 respectively. Calculate Digit Verification of CAS Registry Number 3376-37: (6*3)+(5*3)+(4*7)+(3*6)+(2*3)+(1*7)=92 92 % 10 = 2 So 3376-37-2 is a valid CAS Registry Number.