The CAS Registry Mumber 32570-89-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,2,5,7 and 0 respectively; the second part has 2 digits, 8 and 9 respectively. Calculate Digit Verification of CAS Registry Number 32570-89: (7*3)+(6*2)+(5*5)+(4*7)+(3*0)+(2*8)+(1*9)=111 111 % 10 = 1 So 32570-89-1 is a valid CAS Registry Number.