The CAS Registry Mumber 41000-58-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,1,0,0 and 0 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 41000-58: (7*4)+(6*1)+(5*0)+(4*0)+(3*0)+(2*5)+(1*8)=52 52 % 10 = 2 So 41000-58-2 is a valid CAS Registry Number.