To find the missing number in the equation \( 600 \times __ = 3,000 \), you can divide both sides of the equation by 600.
\[ __ = \frac{3000}{600} \]
Now, calculate the division:
\[ __ = 5 \]
So, \( 600 \times 5 = 3,000 \). Therefore, the missing number is 5.