Return on investment question

[Jonathan Lilly]

I am a little confused about calculating return on investment. Is debt paydown counted towards return on investment? For example, lets say I buy a house for $10,000 down and make $1,000 after expenses and mortgage payments. Lets say the debt paydown on the loan adds up to another $1,000 for the year. Would the return on investment only be the $1,000 profit, $1,000/$10,000, or, would the return on investment be the $1,000 profit plus the $1,000 debt paydown, $2,000/$10,000? Thanks for the help....