The CAS Registry Mumber 85713-24-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,5,7,1 and 3 respectively; the second part has 2 digits, 2 and 4 respectively. Calculate Digit Verification of CAS Registry Number 85713-24: (7*8)+(6*5)+(5*7)+(4*1)+(3*3)+(2*2)+(1*4)=142 142 % 10 = 2 So 85713-24-2 is a valid CAS Registry Number.