The CAS Registry Mumber 30043-37-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,0,0,4 and 3 respectively; the second part has 2 digits, 3 and 7 respectively. Calculate Digit Verification of CAS Registry Number 30043-37: (7*3)+(6*0)+(5*0)+(4*4)+(3*3)+(2*3)+(1*7)=59 59 % 10 = 9 So 30043-37-9 is a valid CAS Registry Number.