What is the place value of 9 in the number 9,000,009

In our (positional) numerical system, the first digit form the right represents the units, and going leftwards, every digit is worth 10 times more than its previous one.

So, in your number, the 9 to the right means "9 units", because it's the rightmost digit.

On the other hand, the leftmost 9 is worth 9 millions, because you shift 6 positions from the right, and the digits are worth:

1st digit from the right: units 2nd digit from the right: tens 3rd digit from the right: hundreds 4th digit from the right: thousands 5th digit from the right: tens of thousands 6th digit from the right: hundreds of thousands 7th digit from the right: millions