9. There are 1000 lamps and 1000 switches, each switch controls all lamps whose numbers are multiples of its own, initially all lamps are on. Now pull the 2, 3, 5 switches, then the number of lamps that are still on is $\qquad$.
9. 499 Only the numbers that are not divisible by any of $2,3,5$, or are exactly divisible by two of them, have their lights on.

In 1 to 1000, there are 500 numbers divisible by 2, 333 numbers divisible by 3, 200 numbers divisible by 5, 166 numbers divisible by $2 \times 3$, 100 numbers divisible by $2 \times 5$, 66 numbers divisible by $3 \times 5$, and 33 numbers divisible by $2 \times 3 \times 5$.

Therefore, the numbers divisible by 2 and 3 but not by 5 are $166-33=133$; the numbers divisible by 2 and 5 but not by 3 are $100-33=67$; the numbers divisible by 3 and 5 but not by 2 are $66-33=33$. The numbers not divisible by any of $2,3,5$ are $1000-(500+$ $333+200-166-100-66+33)=266$.
Thus, there are a total of $133+67+33+266=499$ lights that are on.