The CAS Registry Mumber 83037-75-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,3,0,3 and 7 respectively; the second part has 2 digits, 7 and 5 respectively. Calculate Digit Verification of CAS Registry Number 83037-75: (7*8)+(6*3)+(5*0)+(4*3)+(3*7)+(2*7)+(1*5)=126 126 % 10 = 6 So 83037-75-6 is a valid CAS Registry Number.