Math worksheet asking students to solve a word problem about counting red cars in a parking lot using addition and subtraction.

To find the number of red cars, we need to figure out how many cars are already accounted for and subtract that from the total.

Step 1: Find the total number of known cars.
Add up the number of white, blue, and black cars listed in the table:
* White cars: 15
* Blue cars: 9
* Black cars: 3

$15 + 9 + 3 = 27$

So, there are 27 cars that are white, blue, or black.

Step 2: Subtract the known cars from the total.
The problem states there are 30 cars in the parking lot in total. To find the missing number (the red cars), subtract the sum from Step 1 from the total.

$30 - 27 = 3$

There are 3 red cars in the parking lot.

Final Answer:
3