The CAS Registry Mumber 107049-58-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,7,0,4 and 9 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 107049-58: (8*1)+(7*0)+(6*7)+(5*0)+(4*4)+(3*9)+(2*5)+(1*8)=111 111 % 10 = 1 So 107049-58-1 is a valid CAS Registry Number.