The CAS Registry Mumber 37030-06-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,7,0,3 and 0 respectively; the second part has 2 digits, 0 and 6 respectively. Calculate Digit Verification of CAS Registry Number 37030-06: (7*3)+(6*7)+(5*0)+(4*3)+(3*0)+(2*0)+(1*6)=81 81 % 10 = 1 So 37030-06-1 is a valid CAS Registry Number.