The CAS Registry Mumber 40358-48-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,0,3,5 and 8 respectively; the second part has 2 digits, 4 and 8 respectively. Calculate Digit Verification of CAS Registry Number 40358-48: (7*4)+(6*0)+(5*3)+(4*5)+(3*8)+(2*4)+(1*8)=103 103 % 10 = 3 So 40358-48-3 is a valid CAS Registry Number.