To find the total number of students that attend McCord Middle School, you can use the information that 200 students represent 40% of the total student body.
Let \( x \) be the total number of students. According to the problem:
\[ 0.40x = 200 \]
To find \( x \), divide both sides by 0.40:
\[ x = \frac{200}{0.40} \]
Calculating that gives:
\[ x = 500 \]
So, the total number of students at McCord Middle School is 500 students.