To solve this problem, let's define some variables and build an equation.
Let \( s \) represent the number of students. In this case, \( s = 8 \).
Let \( c \) represent the maximum number of mini candy bars each student can receive. Here, \( c = 4 \).
Now, to find the total number of mini candy bars \( T \) that the teacher should buy, we can use the equation:
\[ T = s \times c \]
Substituting the values we have:
\[ T = 8 \times 4 \]
Calculating this gives:
\[ T = 32 \]
Thus, Noah's teacher should buy a total of 32 mini candy bars.