The CAS Registry Mumber 87579-32-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,7,5,7 and 9 respectively; the second part has 2 digits, 3 and 2 respectively. Calculate Digit Verification of CAS Registry Number 87579-32: (7*8)+(6*7)+(5*5)+(4*7)+(3*9)+(2*3)+(1*2)=186 186 % 10 = 6 So 87579-32-6 is a valid CAS Registry Number.