The CAS Registry Mumber 143057-10-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,3,0,5 and 7 respectively; the second part has 2 digits, 1 and 0 respectively. Calculate Digit Verification of CAS Registry Number 143057-10: (8*1)+(7*4)+(6*3)+(5*0)+(4*5)+(3*7)+(2*1)+(1*0)=97 97 % 10 = 7 So 143057-10-7 is a valid CAS Registry Number.