The CAS Registry Mumber 103230-48-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,3,2,3 and 0 respectively; the second part has 2 digits, 4 and 8 respectively. Calculate Digit Verification of CAS Registry Number 103230-48: (8*1)+(7*0)+(6*3)+(5*2)+(4*3)+(3*0)+(2*4)+(1*8)=64 64 % 10 = 4 So 103230-48-4 is a valid CAS Registry Number.