In a jumble activity learners need to put sentences or paragraphs from a text, or pictures illustrating a text, into the correct order.

Example
The learners put jumbled pictures into a possible order and then read the text to see if their ideas are right.

In the classroom
Ordering jumbled sentences and paragraphs is an excellent way to raise learners' awareness to features of discourse.

Further links:

https://www.teachingenglish.org.uk/article/a-reading-task-role-play

https://www.teachingenglish.org.uk/article/games-question-practice-2

https://www.teachingenglish.org.uk/article/interacting-texts-directed-activities-related-texts-darts