The CAS Registry Mumber 1590410-08-4 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,5,9,0,4,1 and 0 respectively; the second part has 2 digits, 0 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1590410-08: (9*1)+(8*5)+(7*9)+(6*0)+(5*4)+(4*1)+(3*0)+(2*0)+(1*8)=144 144 % 10 = 4 So 1590410-08-4 is a valid CAS Registry Number.