Here is a worksheet on the Latin word roots extra and extro. They mean outside and beyond. This two roots are at the base of a lot of high-frequency words in English, including two adjectives commonly used in your own school–extracurricular and extramural.
Or how about the strong expository verb extrapolate? Surely something we want students to be able to do. Then of course there is always the old standby, extraordinary, literally “beyond ordinary.” Enough said.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.