The CAS Registry Mumber 1357387-29-1 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,3,5,7,3,8 and 7 respectively; the second part has 2 digits, 2 and 9 respectively. Calculate Digit Verification of CAS Registry Number 1357387-29: (9*1)+(8*3)+(7*5)+(6*7)+(5*3)+(4*8)+(3*7)+(2*2)+(1*9)=191 191 % 10 = 1 So 1357387-29-1 is a valid CAS Registry Number.