To find out how many eighth graders took the survey, we need to add the number of eighth graders who prefer pizza and the number who prefer tacos. According to the table:
- Number of 8th graders who prefer Pizza: 54
- Number of 8th graders who prefer Tacos: 81
Now, adding these two numbers together:
54 (Pizza) + 81 (Tacos) = 135
Therefore, the total number of eighth graders who took the survey is 135.