The CAS Registry Mumber 1048-07-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,0,4 and 8 respectively; the second part has 2 digits, 0 and 7 respectively. Calculate Digit Verification of CAS Registry Number 1048-07: (6*1)+(5*0)+(4*4)+(3*8)+(2*0)+(1*7)=53 53 % 10 = 3 So 1048-07-3 is a valid CAS Registry Number.