Students are challenged to solve 8 questions about the probability of lengths of pregnancies by matching up cards.
The cards have 5 categories; the question, the z-score, the Normal curve with area, the calculator command for TI-84, and the probability notation for the answer. I recommend printing each category on a different color paper.
Questions are challenging but attainable, the activity is fun and easy to grade. There are four questions afterward to have students think further about the activity (also good for students who finish the matching part faster than others).
My kids like this activity a lot; it clears up the confusing similarities in probability questions and forces them to justify to each other why an answer is correct.
Key is provided.