This is the 11270th most frequent Russian word.
девятку
"Девятку" is the accusative form of "девятка," which can mean "a nine" (as in the number, a playing card, or a grade of nine) or refer colloquially to a Lada 2109 car model.
Here, 'в девятку' means 'into the nine,' a figurative way to describe hitting the target exactly or succeeding.
Я купил лотерейный билет и выиграл в девятку.
I bought a lottery ticket and hit the jackpot.
In this context, 'девятку' means a grade of nine, representing a scoring system where nine is a high score.
На экзамене я получил девятку по математике.
On the exam, I received a nine in mathematics.
Here, 'девятку' refers to the playing card with the value of nine.