Name: ________________________________ Partner Name: ________________________________
Exponential Growth and Decay of Skittles.
Work in pairs. Each pair should receive two paper plates, and a cup of skittles.
DO NOT EAT THE SKITTLES UNTIL INSTRUCTED TO DO SO.
The Classic Skittle Growth Experiment
1. Place all of your skittles on one plate (your “source” plate). Place 4 Skittles into your cut.
2. Shake the cup and toss Skittles onto the other plate (your “counting” plate).
In the row for Toss “0” in the table below, record the number of Skittles tossed in the 2nd column and the
number of Skittles with “S” side up in the last column.
A. Toss
B. Total
C.
Number of Skittles
Graph on the back of this paper. Only use
Number of
Face Up.
the positive graph.
Skittles
Tossed
3.
Return the Skittles from your counting plate, and add an extra Skittle from your source plate for each one that
had an “S” side up from this toss. Record this new total number of Skittles in your cup in the 2nd column for
Toss 1.
4. Repeat steps 2 and 3 until you have used all Skittles from the source plate.
5. Plot your data from Column B vs. Data from Column A in the graph provided.
6. Describe the relationship that exists between x and y.
 As the value of x increases, the value of y ____________________
 The rate of ___________________ (increases/decreases) becomes _______________(greater/less) as value of
x increases.
 Now let’s construct a pattern (or function ) that models this experiment. Suppose you had started with 8
Skittles on Toss 0, how many total Skittles would you expect to have on Toss 1? ______________________
Using the total number of Skittles that you expected to have in Toss 1, how many total Skittles would you
expect to have in Toss 2? Continue the pattern in the table below.
Toss number
Total number of Skittles
0
8
1
2
3
Remember the Exponential Growth Formula
Exponential Growth:
a = initial amount of Skittles
r = growth rate (probability of an “S”
t = toss number
What is the value of a in your Skittles growth experiment? ________________________
What is the value of r in your Skittles growth experiment? ________________________
Name: ________________________________ Partner Name: ________________________________
Exponential Growth and Decay of Skittles.
Work in pairs. Each pair should receive two paper plates, and a cup of skittles.
DO NOT EAT THE SKITTLES UNTIL INSTRUCTED TO DO SO.
The Classic Skittle Spill (Decay) Experiment
1.
Place all of your skittles on one plate (your “source” plate). Place 4 Skittles into your cut.
Shake and toss the Skittles onto your counting plate, and then count the number with “s” side up. Eat all
skittles that are not “s” side up. Record both the toss number and number of Skittles remaining on your
plate in the table below.
D. Toss
E. Total
F.
Number of Skittles
Graph on the back of this paper. Only use
Number of
Face Up.
the positive graph.
Skittles
Tossed
2.
3.
4.


Return the remaining Skittles to your cup and repeat step 2 until there are no more Skittles left in your cup.
Create a scatterplot of your data in the graph provided.
Describe the relationship that exists between x and y.
As the value of x increases, the value of y ____________________
The rate of ___________________ (increases/decreases) becomes _______________(greater/less) as value of
x increases.
Now let’s construct a pattern (or function ) that models this experiment. Suppose you had started with 80
Skittles on Toss 0, how many total Skittles would you expect to have on Toss 1? ______________________
Using the number of Skittles that you expected to land “S” side up in Toss 0, how many would you expect to
land “S” side up on Toss 1? Continue the pattern in the table below.
Toss number
Total number of Skittles
0
80
1
2
3

Remember the Exponential Growth Formula
Exponential Decay:
a = initial amount of Skittles
r = growth rate (probability of an “S”
t = toss number
What is the value of a in your Skittles decay experiment? ________________________
What is the value of r in your Skittles decay experiment? ________________________