The CAS Registry Mumber 25878-14-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,5,8,7 and 8 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 25878-14: (7*2)+(6*5)+(5*8)+(4*7)+(3*8)+(2*1)+(1*4)=142 142 % 10 = 2 So 25878-14-2 is a valid CAS Registry Number.