The CAS Registry Mumber 80077-15-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,0,0,7 and 7 respectively; the second part has 2 digits, 1 and 5 respectively. Calculate Digit Verification of CAS Registry Number 80077-15: (7*8)+(6*0)+(5*0)+(4*7)+(3*7)+(2*1)+(1*5)=112 112 % 10 = 2 So 80077-15-2 is a valid CAS Registry Number.