The CAS Registry Mumber 78650-12-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,8,6,5 and 0 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 78650-12: (7*7)+(6*8)+(5*6)+(4*5)+(3*0)+(2*1)+(1*2)=151 151 % 10 = 1 So 78650-12-1 is a valid CAS Registry Number.