The most common and most likely answer to this crossword clue is the 3 plus 5 letter word PIE CHART
I've seen this crossword clue in The Daily Telegraph
P
I
E
C
H
A
R
T
More clues leading to the result PIE CHART
- Statistical diagram segment mostly on deer
- Circular graph showing each trip at work
- Graph in Chapter 1 redrawn
- Diagram analysing each trip
- Diagram of interest to Desperate Dan!
- Hip teacher — he put out zany diagram for maths class
- Each trip when reviewed divided circle
- Dish on table widely used by business people!
- Patchier, blurred diagram
Buddy explains!
The straight part
We know that "diagram for maths class" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case diagram for maths class = pie chart.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.