The CAS Registry Mumber 125787-84-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,5,7,8 and 7 respectively; the second part has 2 digits, 8 and 4 respectively. Calculate Digit Verification of CAS Registry Number 125787-84: (8*1)+(7*2)+(6*5)+(5*7)+(4*8)+(3*7)+(2*8)+(1*4)=160 160 % 10 = 0 So 125787-84-0 is a valid CAS Registry Number.