The CAS Registry Mumber 148822-98-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,8,8,2 and 2 respectively; the second part has 2 digits, 9 and 8 respectively. Calculate Digit Verification of CAS Registry Number 148822-98: (8*1)+(7*4)+(6*8)+(5*8)+(4*2)+(3*2)+(2*9)+(1*8)=164 164 % 10 = 4 So 148822-98-4 is a valid CAS Registry Number.