First, calculate the frequency of math scores between (80, 100) according to the proportional relationship, and then calculate the required frequency according to "frequency = frequency × sample size".

Solution: The ratio of the height of each rectangle from left to right is 2: 3: 5: 6: 3: 1.

∴ The frequency of math scores between (80, 100) is

The number of students in this class whose math scores are between (80, 100) is

So the answer is: 33.