The CAS Registry Mumber 126314-58-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,6,3,1 and 4 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 126314-58: (8*1)+(7*2)+(6*6)+(5*3)+(4*1)+(3*4)+(2*5)+(1*8)=107 107 % 10 = 7 So 126314-58-7 is a valid CAS Registry Number.