Prepare a set of cards for class. Each card will have an answer and a question written on it.
As students come to class, hand each of them a card.
Keep one card for yourself and hand out the remaining cards to students who wish them.  Then, beginning with your card, read the "I have ..." part and then the "Who has ... " part.   The student who has the answer to your question will then read his or her card.   The student with the answer to that question reads his card and so on until you have gone through the entire set of cards.

This is a good technique for reviewing for a test.   It gets every student involved.

Below is a set of I Have ... Who Has ... cards to use with a review of derivatives.   I used this activity near Halloween; hence, the question #30 and answer #1.   I would hold card #1.

I HAVE ...        
    WHO HAS ...        
1.   pumpkin pi
 1.   (uv)'=uv'+vu'
2.   24x2

2.   100th derivative of y = 5x10

3.   0
3.   the Product Rule
4.   (uv)'=uv'+vu'

4.   (fg)'

5.  
5.   (tan 2x)'
6.   2 sec2(2x)

 6.   (tan 2x)'

7.   u' + v'
 7.   (cos 2x)'
8.   -2 sin2x

8.   the derivative of y = 12x

9.   12
9.   the derivative of y = x8
10.   8x7

10.   der rule

11.   der rule
11.   der rule
12.   sec(x) tan(x)

12.   the derivative of velocity with respect to time
13.   acceleration
 13.   der rule
14.   16v

14.   der rule

15.   f '(x) - g '(x)
 15.   the derivative of 12x - 5x3
16.   12 - 15x2

16.   der rule

17.   der rule
17.   der rule
18.   der rule

18.   der rule

19.   der rule
19.   der rule
20.   der rule

20.   the derivative of displacement with respect to time

21.   velocity
 21.   der rule
22. x sec2x + tan x

22.   der rule
23.   der rule
 23.   der rule
24.   1/8

24.   der rule

25.   der rule
25.   der rule
26.   - 2sin x

26.   der rule

27.   der rule
 27.   the derivative of x2012

28.   2012x2011

28.   instantaneous rate of change of y = x3 at x = 1

29.   3
 29.   average rate of change of y = x3 over the interval [1, 2]
30.   7

 30.   circumference of a jack-o-lantern divided by its diameter