The CAS Registry Mumber 1602492-05-6 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,6,0,2,4,9 and 2 respectively; the second part has 2 digits, 0 and 5 respectively. Calculate Digit Verification of CAS Registry Number 1602492-05: (9*1)+(8*6)+(7*0)+(6*2)+(5*4)+(4*9)+(3*2)+(2*0)+(1*5)=136 136 % 10 = 6 So 1602492-05-6 is a valid CAS Registry Number.